Subcutaneous vascular access ports

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 12/697,190, titled SUBCUTANEOUS VASCULAR ACCESS PORTS AND RELATED SYSTEMS, METHODS, AND IMPLANTATION FEATURES, filed on Jan. 29, 2010 now U.S. Pat. No. 8,337,465, which is a continuation-in-part of U.S. patent application Ser. No. 12/480,678, titled TISSUE MANAGEMENT METHODS, APPARATUS, AND SYSTEMS, filed Jun. 8, 2009 now U.S. Pat. No. 8,409,228, and which claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/148,372, titled VASCULAR ACCESS METHODS, APPARATUS AND SYSTEMS, filed on Jan. 29, 2009, and which further claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/229,023, titled SURGICALLY IMPLANTED DIRECT VASCULAR ACCESS PORT METHOD AND APPARATUS, filed on Jul. 28, 2009, the entire contents of each of which are hereby incorporated by reference herein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

The invention was made with support from the U.S. Government under Grant No. SBIR R44 CA 139608, which was awarded by the National Institutes of Health. The U.S. Government has certain rights in the invention.

TECHNICAL FIELD

The present disclosure relates to subcutaneous vascular access ports and related systems and methods.

BRIEF DESCRIPTION OF THE DRAWINGS

The written disclosure herein describes illustrative embodiments that are non-limiting and non-exhaustive. Reference is made to certain of such illustrative embodiments that are depicted in the figures, in which:

<figref idref="DRAWINGS">FIG. 1</figref> is a perspective view of an embodiment of a vascular access port;

<figref idref="DRAWINGS">FIG. 2</figref> is a front elevation view thereof;

<figref idref="DRAWINGS">FIG. 3</figref> is a rear elevation view thereof;

<figref idref="DRAWINGS">FIG. 4</figref> is a top plan view thereof;

<figref idref="DRAWINGS">FIG. 5</figref> is a bottom plan view thereof;

<figref idref="DRAWINGS">FIG. 6</figref> is a right side elevation view thereof, wherein a left side elevation view is a mirror image of the right side elevation view;

<figref idref="DRAWINGS">FIG. 7</figref> is a cross-sectional view of the vascular access port of <figref idref="DRAWINGS">FIG. 1</figref> taken along the view line <b>7</b>-<b>7</b> in <figref idref="DRAWINGS">FIG. 2</figref>;

<figref idref="DRAWINGS">FIG. 8</figref> is a perspective partial cutaway view of the vascular access port of <figref idref="DRAWINGS">FIG. 1</figref> coupled with a vessel;

<figref idref="DRAWINGS">FIG. 9A</figref> is a perspective view of a stage of an illustrative method of implanting an embodiment of a vascular access port in a patient depicting the creation of an incision;

<figref idref="DRAWINGS">FIG. 9B</figref> is a perspective view of another stage of the method of <figref idref="DRAWINGS">FIG. 9A</figref> in which a vessel is exposed;

<figref idref="DRAWINGS">FIG. 9C</figref> is a perspective view of another stage of the method of <figref idref="DRAWINGS">FIG. 9A</figref> in which an attachment is made between the vascular access port and the vessel;

<figref idref="DRAWINGS">FIG. 9D</figref> is a perspective view of another stage of the method of <figref idref="DRAWINGS">FIG. 9A</figref> in which additional attachments have been made between the vascular access port and the vessel;

<figref idref="DRAWINGS">FIG. 9E</figref> is a perspective view of another stage of the method of <figref idref="DRAWINGS">FIG. 9A</figref> in which the incision has been closed;

<figref idref="DRAWINGS">FIG. 10A</figref> is a perspective view of a stage of another illustrative method of implanting an embodiment of a vascular access port depicting the creation of an incision in the skin of a patient;

<figref idref="DRAWINGS">FIG. 10B</figref> is a perspective view of another stage of the method of <figref idref="DRAWINGS">FIG. 10A</figref> in which adventitia of a vessel is isolated;

<figref idref="DRAWINGS">FIG. 10C</figref> is a perspective view of another stage of the method of <figref idref="DRAWINGS">FIG. 10A</figref> in which in incision is made in the adventitia;

<figref idref="DRAWINGS">FIG. 10D</figref> is a perspective view of another stage of the method of <figref idref="DRAWINGS">FIG. 10A</figref> in which a pocket is formed in the adventitia;

<figref idref="DRAWINGS">FIG. 10E</figref> is a perspective view of another stage of the method of <figref idref="DRAWINGS">FIG. 10A</figref> in which an embodiment of a vascular access port is inserted into the pocket;

<figref idref="DRAWINGS">FIG. 10F</figref> is a perspective view of another stage of the method of <figref idref="DRAWINGS">FIG. 10A</figref> in which attachments have been made between the vascular access port and the vessel;

<figref idref="DRAWINGS">FIG. 10G</figref> is a perspective view of another stage of the method of <figref idref="DRAWINGS">FIG. 10A</figref> in which the incision in the skin of the patient has been closed;

<figref idref="DRAWINGS">FIG. 11A</figref> is a cross-sectional view of a palpations stage of an illustrative method relating to the creation and use of a buttonhole access site to access a lumen of a vessel;

<figref idref="DRAWINGS">FIG. 11B</figref> is a cross-sectional view of another stage of the method of <figref idref="DRAWINGS">FIG. 11A</figref> in which a needle having a sharp tip is inserted into the lumen of the vessel via an embodiment of a vascular access port;

<figref idref="DRAWINGS">FIG. 11C</figref> is a cross-sectional view of another stage of the method of <figref idref="DRAWINGS">FIG. 11A</figref> in which pressure is applied to the skin of the patient;

<figref idref="DRAWINGS">FIG. 11D</figref> is a cross-sectional view of another stage of the method of <figref idref="DRAWINGS">FIG. 11A</figref> in which an insertion tract and a buttonhole access site have been formed;

<figref idref="DRAWINGS">FIG. 11E</figref> is a cross-sectional view of another stage of the method of <figref idref="DRAWINGS">FIG. 11A</figref> in which a needle having a blunt tip is inserted into the lumen of the vessel via the insertion tract, the vascular access port, and the buttonhole access site;

<figref idref="DRAWINGS">FIG. 12</figref> is a cross-sectional view of a stage of another illustrative method relating to the creation and use of a buttonhole access site to access a lumen of a vessel;

<figref idref="DRAWINGS">FIG. 13</figref> is a bottom plan view of a filleted vessel that bears an embodiment of a buttonhole access site that has been created via an embodiment of a vascular access port;

<figref idref="DRAWINGS">FIG. 14A</figref> is a perspective view of an embodiment of a vascular access system that can be used for hemodialysis;

<figref idref="DRAWINGS">FIG. 14B</figref> is a perspective view of another embodiment of a vascular access system that can be used for hemodialysis;

<figref idref="DRAWINGS">FIG. 15</figref> is a top perspective view of another embodiment of a vascular access port;

<figref idref="DRAWINGS">FIG. 16</figref> is a cross-sectional view of the vascular access port of <figref idref="DRAWINGS">FIG. 15</figref>;

<figref idref="DRAWINGS">FIG. 17</figref> is a bottom perspective view of the vascular access port of <figref idref="DRAWINGS">FIG. 15</figref>;

<figref idref="DRAWINGS">FIG. 18</figref> is a top perspective view of an embodiment of a clip that can be coupled with the vascular access port of <figref idref="DRAWINGS">FIG. 15</figref>;

<figref idref="DRAWINGS">FIG. 19</figref> is a bottom perspective view of the vascular access port of <figref idref="DRAWINGS">FIG. 15</figref> coupled with the clip of <figref idref="DRAWINGS">FIG. 18</figref>;

<figref idref="DRAWINGS">FIG. 20</figref> is a perspective view of an embodiment of a percutaneous implantation assembly that can be used to implant the vascular access port of <figref idref="DRAWINGS">FIG. 15</figref> within a patient;

<figref idref="DRAWINGS">FIG. 21</figref> is a partially exploded perspective view of the percutaneous implantation assembly of <figref idref="DRAWINGS">FIG. 20</figref>;

<figref idref="DRAWINGS">FIG. 22A</figref> is a cross-sectional view of a stage of an implantation procedure in which a portion of the percutaneous implantation assembly of <figref idref="DRAWINGS">FIG. 20</figref> is advanced over another portion of the percutaneous implantation assembly;

<figref idref="DRAWINGS">FIG. 22B</figref> is a cross-sectional view of another stage of the implantation procedure of <figref idref="DRAWINGS">FIG. 22A</figref> in which a portion of a vessel wall that has been drawn into the percutanous implantation assembly is cut;

<figref idref="DRAWINGS">FIG. 22C</figref> is a cross-sectional view of another stage of the implantation procedure of <figref idref="DRAWINGS">FIG. 22A</figref> in which an embodiment of a vascular access port is advanced toward the vessel;

<figref idref="DRAWINGS">FIG. 22D</figref> is a cross-sectional view of another stage of the implantation procedure of <figref idref="DRAWINGS">FIG. 22A</figref> in which stops of the vascular access port are in contact with retention prongs of a clip;

<figref idref="DRAWINGS">FIG. 22E</figref> is a cross-sectional view of another stage of the implantation procedure of <figref idref="DRAWINGS">FIG. 22A</figref> in which a clip to which the vascular access port is attached has been ejected from the implantation assembly;

<figref idref="DRAWINGS">FIG. 23A</figref> is a cross-sectional view of a stage of method of using an implanted vascular access port;

<figref idref="DRAWINGS">FIG. 23B</figref> is cross-sectional view of another stage of the method of <figref idref="DRAWINGS">FIG. 23A</figref> in which healing has taken place;

<figref idref="DRAWINGS">FIG. 23C</figref> is a cross-sectional view of another stage of the method of <figref idref="DRAWINGS">FIG. 23A</figref> in which an access device is advanced through the vascular access port;

<figref idref="DRAWINGS">FIG. 24</figref> is a top perspective view of another embodiment of a vascular access port coupled with another embodiment of a clip;

<figref idref="DRAWINGS">FIG. 25</figref> is a bottom perspective view of the vascular access port and the clip of <figref idref="DRAWINGS">FIG. 24</figref>;

<figref idref="DRAWINGS">FIG. 26</figref> is a perspective view of another embodiment of a vascular access port; and

<figref idref="DRAWINGS">FIG. 27</figref> is a perspective view of an embodiment of a vascular access system that can be used for the external treatment of blood.

DETAILED DESCRIPTION

Certain embodiments of vascular access ports described herein are configured to be implanted subcutaneously in a patient for relatively long or indefinite periods. The vascular access ports can be implanted in any suitable manner and can be substantially fixed relative to a vessel wall once implanted. For example, in some implantation methods, a bottom surface of a vascular access port placed in contact with the tunica adventitia of a vessel and the port is secured to the vessel via one or more sutures that extend through at least a portion of every layer of the vessel. In further embodiments, a portion of the tunica adventitia is separated or removed from a blood vessel such that the bottom surface of a port is relatively close to the tunica media layer of the blood vessel, and the port is secured to the vessel via one or more sutures that extend through at least a portion of the tunica adventitia layer and substantially entirely through the media and the tunica intima layers. The surface of the port that contacts the vessel wall can comprise an opening through which an access device, such as a needle, can be inserted into a lumen of the blood vessel. The vascular access ports can be well-suited for buttonhole cannulation techniques in which buttonhole access sites are created in vessel walls and/or are used to access the vessels. The term “buttonhole” is used herein in its ordinary sense in the field of vascular access (e.g., in the field of hemodialysis), particularly in the context of cannulation techniques, and the term can include single-site cannulation holes that are approximately the same size as access devices that are inserted therethrough (e.g., needles or other cannulation devices), and that can permit relatively easy insertion of the access devices as compared with other areas along a vessel wall. Similarly, the ports can be well-suited for the creation and/or use of tracts through the skin of a patient through which the buttonholes can be repeatedly accessed. These and other features and advantages of various embodiments of vascular access ports, of systems that employ the ports, and of methods of implanting and using the ports will be apparent from the disclosure herein.

<figref idref="DRAWINGS">FIGS. 1-7</figref> illustrate an embodiment of a vascular access port <b>100</b>. The vascular access port <b>100</b> includes a base <b>102</b> and a body <b>104</b>. In the illustrated embodiment, the base <b>102</b> and the body <b>104</b> are integrally formed as a unitary piece, and the body <b>104</b> extends away from the base <b>102</b>. The base <b>102</b> is elongated in a longitudinal direction. In particular, the illustrated base <b>102</b> defines a substantially rectangular perimeter <b>106</b> that extends a greater distance in a longitudinal direction than it does in a transverse direction (see, e.g., <figref idref="DRAWINGS">FIG. 5</figref>). The edges and corners of the rectangular perimeter <b>106</b> can be rounded, which can prevent trauma to surrounding tissue when the vascular access port <b>100</b> is implanted.

The base <b>102</b> can include a base surface or bottom surface <b>108</b> that is configured to face a vessel when the vascular access port <b>100</b> is coupled to the vessel. The bottom surface <b>108</b> can be configured to conform to a contour of a wall of the vessel. For example, the bottom surface <b>108</b> of the base <b>102</b> can be bowed in the transverse direction and can have a radius of curvature that is substantially the same as a radius of curvature of an outer surface of a vessel to which the vascular access port <b>100</b> is to be attached. The bowed bottom surface <b>108</b> can define a cavity <b>110</b> (see <figref idref="DRAWINGS">FIGS. 2 and 3</figref>) into which at least a portion of a circumference of a vessel can be received. In the illustrated embodiment, the width and the curvature of the bottom surface <b>108</b> are such that the cavity <b>110</b> is sized to receive a substantial portion of the circumference of a vessel therein. Such a configuration can permit the bottom surface <b>108</b> to form a stable contact with the vessel. Other suitable arrangements are also possible, as discussed below.

The base <b>102</b> can include one or more connection flanges <b>112</b> that extend about a least a portion of a periphery of the base <b>102</b>. In the illustrated embodiment, a first connection flange <b>112</b> extends about a front end of the base <b>102</b> and a second connection flange <b>112</b> is at a back end of the base <b>102</b>. One or more attachment channels or attachment passages <b>114</b> can extend through the connection flanges <b>112</b>. The attachment passages <b>114</b> can be configured to permit one or more ties or attachment devices <b>116</b> to extend therethrough so as to attach the vascular access port <b>100</b> to a vessel (see, e.g., <figref idref="DRAWINGS">FIGS. 8, 9C, 10F, 11A, and 12</figref>), as discussed further below. Any suitable attachment devices <b>116</b> may be used, such as one or more sutures, pinch rings, hooks, or wires. Accordingly, in some embodiments, one or more of the attachment passages <b>114</b> may be referred to as suture holes. As further discussed below, in the illustrated embodiment, the base <b>102</b> includes a centrally situated attachment passage <b>114</b> at each of the front and rearward ends thereof.

The body <b>104</b> can extend upwardly from the base <b>102</b>. In the illustrated embodiment, the body rises upwardly along a central vertical longitudinal plane <b>120</b> (see <figref idref="DRAWINGS">FIGS. 2 and 4</figref>) of the vascular access port <b>100</b>. With reference to <figref idref="DRAWINGS">FIG. 4</figref>, the body <b>104</b> can expand outwardly from the central vertical longitudinal plane <b>120</b> and can widen in a rearward direction. Additionally, as shown in <figref idref="DRAWINGS">FIGS. 3, 4, and 6</figref>, a pinnacle region <b>122</b> of the body <b>104</b> can be positioned along the central vertical longitudinal plane <b>120</b> and at approximately a longitudinal center of the body <b>104</b>. It is noted that directional terms, such as bottom, front, and rearward, are used relative to the orientation of the vascular access port <b>100</b> shown in <figref idref="DRAWINGS">FIG. 1</figref>. Such directional terms are not intended to limit the possible orientations of the vascular access port <b>100</b> within a patient. For example, in some embodiments, the front end of the vascular access port <b>100</b> may be oriented upstream from the rearward end thereof when the port <b>100</b> is coupled to a vessel, whereas in other embodiments, the front end may be oriented downstream from the rearward end.

A guidance passageway <b>130</b> can extend through the body <b>104</b>. In the illustrated embodiment, the guidance passageway <b>130</b> includes a funnel region <b>132</b> and a channel <b>134</b>. The funnel region <b>132</b> defines a relatively large entry mouth <b>136</b>, which extends about or circumscribes the proximal end or proximal opening thereof, and the funnel region <b>132</b> narrows from the entry mouth <b>136</b> in a forward and downward direction. In the illustrated embodiment, a forward end of the funnel region <b>132</b> transitions into the channel <b>134</b>. The funnel region <b>132</b> can include a base surface <b>138</b> that projects rearwardly from the channel <b>134</b> and that flares outwardly in the rearward direction. As shown in <figref idref="DRAWINGS">FIG. 7</figref>, the base surface <b>138</b> of the funnel region <b>132</b> can be angled upwardly (in a rearward direction) relative to the bottom surface <b>108</b> of the base <b>102</b>. The funnel region <b>132</b> can further include wings <b>140</b> that each curve upwardly and outwardly from the base surface <b>138</b> and that are each joined to a backstop portion <b>142</b> at a forward end thereof. As shown in <figref idref="DRAWINGS">FIGS. 4 and 5</figref>, the wings <b>140</b> can extend outwardly past the perimeter <b>106</b> of the base <b>102</b> so as to provide for a wide entry mouth <b>136</b> of the funnel region <b>132</b>. The backstop portion <b>142</b> can rise upwardly from an upper surface of the channel <b>134</b> and may include a surface that is directed substantially vertically. The backstop portion <b>142</b> can span the channel <b>134</b>, and at least a portion thereof can be positioned directly above the channel <b>134</b>.

The funnel region <b>132</b> can fully encompass an entrance end of the channel <b>134</b> and can encourage a tip of an access device <b>144</b>, such as a needle (see <figref idref="DRAWINGS">FIG. 11B</figref>), to enter the channel <b>134</b>. The funnel region <b>132</b> thus can serve as an enlarged target area that can assist in directing an access device <b>144</b> to a desired portion of a vessel, as discussed further below. The funnel region <b>132</b> can comprise a material that can prevent or discourage a tip of an access device <b>144</b> from embedding therein or removing a portion thereof as the tip moves toward the channel <b>134</b>. For example, in various embodiments, the funnel region <b>132</b> can comprise titanium, stainless steel, a rigid plastic, or a similar material.

At least a portion of the entry mouth <b>136</b> of the funnel region <b>132</b> can include a palpation projection <b>146</b>, such as a palpation ridge. In the illustrated embodiment, the palpation projection <b>146</b> is substantially U-shaped and extends over the wings <b>140</b> and the backstop portion <b>142</b> of the funnel region <b>132</b>, and the pinnacle region <b>122</b> of the body <b>104</b> is located at a forward end of the palpation projection <b>146</b>. The palpation projection <b>146</b> can be rounded or radiused so as to be free from sharp edges that could lead to tissue erosion. As further discussed below, the palpation projection <b>146</b> can be used to locate the vascular access port <b>100</b> and/or confirm an orientation thereof when the port <b>100</b> is positioned subcutaneously in a patient.

The entry mouth <b>136</b> of the funnel region <b>132</b> may be used to assist in achieving hemostasis after removal of an access device <b>144</b> from the vascular access port <b>100</b>. To this end, the palpation projection <b>146</b> may substantially define a plane, in some embodiments. As shown in <figref idref="DRAWINGS">FIG. 6</figref>, the palpation projection <b>146</b> of the illustrated embodiment is nearly or substantially planar, as it is not perfectly planar due to a slight curvature in the longitudinal direction. The palpation projection <b>146</b> also exhibits a slight curvature in the transverse direction, as can be seen in <figref idref="DRAWINGS">FIG. 3</figref>. Moreover, in the illustrated embodiment, a rearward edge of the entry mouth <b>136</b> smoothly transitions into the palpation projection <b>146</b> at either end thereof and is only slightly below the substantially planar region defined by the palpation projection <b>146</b>. Accordingly, as further discussed below, a seal can readily be formed about a periphery of the entry mouth <b>136</b> of an implanted vascular access port <b>100</b> by pressing tissue that surrounds the port <b>100</b> against the entry mouth <b>136</b>.

With reference to <figref idref="DRAWINGS">FIG. 7</figref>, the channel <b>134</b> can extend through the base <b>102</b>, and a bottom end of the channel <b>134</b> can define an opening <b>150</b> in the bottom surface <b>108</b> of the base <b>102</b>. The opening <b>150</b> may be referred to as a distal opening <b>150</b> of the guidance passageway <b>130</b>. The channel <b>134</b> can be configured to constrain movement of one or more access devices <b>144</b> inserted individually therethrough along a predetermined or repeatable path toward the opening <b>150</b>. Accordingly, when the vascular access device <b>100</b> is fixed relative to a vessel, the channel <b>134</b> and the opening <b>150</b> can cause the one or more access devices <b>144</b> to cannulate the same portion of the vessel. In certain embodiments, the channel <b>134</b> defines a substantially constant inner diameter D along a length thereof, which can constrain the movement of an access device <b>144</b> that has an outer diameter that is slightly smaller than the diameter D. For example, in the illustrated embodiment, the channel <b>134</b> is substantially cylindrical and can constrain movement of a substantially cylindrical access device <b>144</b> (e.g., a fistula needle) that has an outer diameter slightly smaller than the diameter D (see <figref idref="DRAWINGS">FIG. 11B</figref>). The diameter D and/or the length of the channel <b>134</b> can be selected to achieve a desired amount of constraint for a given access device <b>144</b>.

With continued reference to <figref idref="DRAWINGS">FIG. 7</figref>, the channel <b>134</b> can define a central axis AX, which can define an acute angle α relative to the bottom surface <b>108</b>. For example, in the illustrated embodiment, the axis AX and a longitudinal line along the bottom surface <b>108</b> form the angle α. In <figref idref="DRAWINGS">FIG. 7</figref>, the longitudinal line is represented in <figref idref="DRAWINGS">FIG. 7</figref> by a line L that defines a longitudinal length of the base <b>10</b>. When the vascular access port <b>100</b> is connected to a vessel, the longitudinal line L can be substantially parallel to a longitudinal axis of a lumen of the vessel (see <figref idref="DRAWINGS">FIG. 11A</figref>). Accordingly, in the illustrated embodiment, the channel <b>134</b> can constrain movement of an access device <b>144</b> along a path that is both nonparallel and non-orthogonal to the lumen of the vessel. In particular, the channel <b>134</b> can constrain movement of the access device <b>144</b> along a path that is at or is approximately at the angle α relative to the lumen of the vessel. In various embodiments, the angle α can have a value that is no greater than about 15, 20, 25, 30, 35, 45, or 60 degrees; can have a value that is no less than about 10, 15, 20, 25, 30, 35, 45, or 60 degrees; or can have a value that is within a range of from about 30 degrees to about 60 degrees, from about 15 degrees to about 45 degrees, or from about 20 degrees to about 35 degrees. As further discussed below, some protocols for the creation and use of buttonhole cannulation sites can require introduction of a needle into a vessel at a designated acute angle. Accordingly, certain embodiments of the vascular access port <b>100</b> can be configured for use with such protocols, and the angle α can be selected to correspond with the angle designated by the protocol.

As previously discussed, the diameter D defined by the channel <b>134</b> can be larger than a diameter of an access device <b>144</b> that is inserted through the channel <b>134</b>. In some embodiments, the channel <b>134</b> is larger than the access device <b>144</b> by a sufficient amount to allow the access device <b>144</b> to pass through it easily or with little or no resistance. Reduction or elimination of insertion and removal forces between an access device <b>144</b> and the channel <b>134</b> can assist in maintaining a secure attachment between the vascular access port <b>100</b> and a vessel over the course of multiple insertion and removal events. Moreover, in the illustrated embodiment, the channel <b>134</b> is open, unobstructed, clear, free, or vacant. Stated otherwise, the channel <b>134</b> is devoid of closure apparatus, such as, for example, septums, valves, obturators, etc., which could be used to selectively open the channel <b>134</b> prior to or during insertion of an access device <b>144</b> therein, or which could be used to selectively close the channel <b>134</b> during or after removal of an access device <b>144</b> therefrom. The term “closure apparatus,” as used herein, is directed to mechanical, electromechanical, or other synthetic, foreign, or non-native devices or systems that may be manufactured outside of a patient and introduced into a patient, but does not include natural or patient-generated materials that may close the channel <b>134</b>, such as, for example, clotted blood, tissue ingrowth, or vascular structures, such as a neointima or a pseudo vessel wall.

In certain embodiments, a configuration of the channel <b>134</b>, or more generally, the guidance passageway <b>130</b>, can remain unchanged upon insertion of an access device <b>144</b> therein or removal of an access device <b>144</b> therefrom, which may result, at least in part, from an absence of closure apparatus within the channel <b>134</b> or the guidance passageway <b>130</b>. More generally, a configuration of the vascular access port <b>100</b> can remain unchanged upon insertion of an access device <b>144</b> therein or removal of an access device <b>144</b> therefrom. Stated otherwise, in certain embodiments, no portion of one or more of the channel <b>134</b>, the guidance passageway <b>130</b>, and the vascular access port <b>100</b> may be deformed, rotated, translated, pivoted, expanded, contracted, or otherwise moved relative to remaining portions of one or more of the channel <b>134</b>, the guidance passageway <b>130</b>, and the vascular access port <b>100</b>. Any resistive forces to the insertion or removal of an access device <b>144</b> that might be provided by closure apparatus thus are absent during use of the vascular access port <b>100</b>. Methods by which hemostasis may be achieved via the vascular access port <b>100</b> in the absence of closure apparatus are discussed below.

Manufacture of embodiments of the vascular access port <b>100</b> can be facilitated by their lack of closure apparatus. For example, in the illustrated embodiment, the vascular access port <b>100</b> comprises a unitary piece and/or comprises a single material, and it is devoid of moving parts. Likewise, in the illustrated embodiment, the guidance passageway <b>130</b> is defined by a single unitary piece and/or by a single material, and it is devoid of moving parts. Other or further embodiments may comprise multiple parts that are fixedly attached to each other in a non-separable fashion. Embodiments of the vascular access port <b>100</b> can be manufactured via any suitable method, such as machining, die casting, injection molding, etc., and may comprise any suitable biocompatible material, such as, for example, titanium, stainless steel, rigid plastic, etc. In some embodiments, the vascular access port <b>100</b> comprises a resorbable material. For example, in various embodiments, the vascular access port <b>100</b> can comprise one or more of caprilactone and glycolide (e.g., Panacryl, in proportions of about 90% and 10%, respectively); ε-caprolactone; cellulose; ethylene oxide with propylene oxide (e.g., Pleuronic F-108); ethylene oxide with block polymer (e.g., DynaGraft proloxamer); glycolide, dioxanone, and trimethylene carbonate (e.g., Biosyn, in proportions of about 60%, 14%, and 26%, respectively); glycolide and ε-caprolactone (e.g., Monocryl); hyaluronic acid ester (e.g., Hyaff); poly(butylene-terephthalate)-co-(polyethyleneglycol) (e.g., Poly-active, Osteo-active); polydioxanon (e.g., PDS); polyethyleenoxyde, polyglactin (e.g. Vicryl, Vicryl Rapide, Vicryl Plus, Polysorb); poly-glecapron (e.g., Monocryl); polyglycolic acid (e.g., Dexon); polyglyconate (e.g., Maxon); polyglyceride (e.g., Trilucent); polylactic acid (e.g., PLLA); poly L-lactic acid (PLLA) and polyglycolic acid (PGA) (e.g., in proportions of about 82% and 18%, respectively); poly L-lactic acid (PLLA) and copolymer (e.g., Lactosorb); poly-L-lactide, poly-D-lactide, and poly-glycolide; polyvinylalcohol (e.g., Bioinblue); polysaccharide; and propylene oxide.

In other embodiments, the vascular access port <b>100</b> can be formed of a combination of materials. For example, in some embodiments, the guidance passageway <b>130</b> can be formed of a material that remains rigid indefinitely, or for a relatively long period, such as titanium, stainless steel, or a first type of resorbable material, and other portions of the vascular access port <b>100</b> can comprise a resorbable material, such as, for example, a second type of resorbable material that is resorbed within the body of a patient much quicker than is the first type of resorbable material.

With reference to <figref idref="DRAWINGS">FIG. 5</figref>, the bottom surface <b>108</b> of the base <b>102</b> can include any suitable ingrowth-inducing covering <b>152</b>, which can facilitate integration or ingrowth of tissue in order to provide or enhance an attachment between a vessel and the vascular access port <b>100</b>. In some embodiments, the ingrowth-inducing covering comprises a porous or roughened texture, which can be formed in any suitable manner. For example, in some embodiments, the texture is provided by compaction and sintering of metallic beads or powders, such as titanium beads, onto the bottom surface <b>108</b>. In some embodiments, the beads may have a diameter of about 5 thousandths of an inch (i.e., approximately 0.13 millimeters) or smaller. In other or further embodiments, the ingrowth-inducing covering <b>152</b> can be formed by machining, sandblasting, laser etching, or injection molding of the bottom surface <b>108</b>, or by attaching to the bottom surface <b>108</b> a fabric, such as polyester, Dacron®, or e-PTFE.

The ingrowth-inducing covering <b>152</b> can extend over the entire bottom surface <b>108</b> of the base <b>102</b>, as shown in the illustrated embodiment, or over a significant portion thereof. In some embodiments, it can be desirable for the ingrowth-inducing covering <b>152</b> to cover a region that is forward of and/or that encompasses the opening <b>150</b> so as to provide a secure attachment between a vessel and the base <b>102</b> in this region, which can assist in ensuring that access devices <b>144</b> inserted through the opening <b>150</b> are consistently and repeatedly directed to the same portion of the vessel. For example, an attachment area AR may be defined over which it is desirable to provide a secure attachment to a vessel. The attachment area AR may be encompassed by a series of attachment passages <b>114</b> through which one or more attachment devices <b>116</b> may be advanced through the sidewall of a vessel into the lumen of a vessel to couple the vascular access device <b>100</b> to a vessel. The attachment area AR likewise may be covered by the ingrowth-inducing covering <b>152</b> which can provide a further connection between the vascular access port <b>100</b> and an outer layer of the vessel (e.g., the adventitia or media). The attachment area AR can surround the opening <b>150</b>, as shown. The attachment area AR may also be referred to as an attachment region.

In some embodiments, the base <b>102</b> can be provided with an adhesive (not shown) in addition to or instead of the ingrowth-inducing covering <b>152</b> to provide a secure attachment between the base <b>102</b> and a vessel. For example, in some embodiments, the adhesive can comprise cyanoacrylate or fibrin glue.

It can be desirable for the vascular access port <b>100</b> to be configured for sufficiently secure attachment to a vessel such that the port <b>100</b> remains fixed relative to the vessel when it is influenced by forces from a needle or other access device <b>144</b>. For example, attachment devices <b>116</b> coupled to the attachment passages <b>114</b>, tissue attached to the ingrowth-inducing covering <b>152</b>, and/or a bond provided by adhesives can resist relative longitudinal movement between the vascular access port <b>100</b> and the vessel when a tip of the access device <b>144</b> is urged forwardly along the funnel region <b>132</b> or forwardly within the channel <b>134</b>. Similarly, such attachment features can resist relative rotational movement between the vascular access port <b>100</b> and the vessel when a tip of the access device <b>144</b> presses downwardly on either of the wings <b>140</b>.

In some embodiments, it can be desirable to constrain the ingrowth-inducing covering <b>152</b> to the bottom surface <b>108</b> of the base <b>102</b>, such as when it is desired to discourage, inhibit, or prevent the body <b>104</b> from attaching to surrounding tissue when the vascular access port <b>100</b> is implanted in a patient. For example, vessels can be somewhat mobile relative to surrounding tissue, and it may be more desirable for the vascular access port <b>100</b> to remain fixed relative to a vessel rather than relative to the tissue that surrounds the vessel. Accordingly, in some embodiments, the body <b>104</b> is relatively smooth. In other embodiments, at least a portion of the body <b>104</b> can comprise an ingrowth-inducing covering <b>152</b>.

In some embodiments, at least a portion of the vascular access port <b>100</b> can include a covering (not shown), such as a coating and/or an embedded portion, that comprises one or more materials or agents that provide antiseptic, antimicrobial, antibiotic, antiviral, antifungal, anti-infection, or other desirable properties to the vascular access port <b>100</b>, such as the ability to inhibit, decrease, or eliminate the growth of microorganisms at or near a surface of the port. For example, in various embodiments, the vascular access port <b>100</b> can comprise one or more of silver, platinum, gold, zinc, iodine, phosphorus, bismuth, alexidine, 5-flurouracil, chlorhexidine, sulfadiazine, benzalkonium chloride, heparin, complexed heparin, benzalkonoium chloride, 2,3 dimercaptopropanol, ciprofloxacin, cosmocil, cyclodextrin, dicloxacillin, EDTA, EGTA, myeloperoxidase, eosinophil peroxidase, fusidic acid, hexyl bromide, triclosan, polymyxin B, isopropanol, minocycline rifampin, minocycline EDTA, octenidine, orthophenyl phenol, triclocarban, triclosan, cephazolin, clindamycin, dicloxacillin, fusidic acid, oxacillin, rifampin, antibodies, peptides, polypeptides, free fatty acids, and oxidative enzymes. In some embodiments, the coating and/or the embedded material may be separate or independent from (e.g., non-coextensive with) the ingrowth-inducing covering <b>152</b>. For example, in some embodiments, the ingrowth-inducing covering <b>152</b> is constrained to the base <b>102</b> of the vascular access port <b>100</b>, whereas an antimicrobial covering is constrained to the body <b>104</b> of the vascular access port <b>100</b>.

In the illustrated embodiment, a forward face <b>156</b> of the body <b>104</b> rises smoothly from the base <b>102</b> and is angled rearwardly. As shown in <figref idref="DRAWINGS">FIG. 7</figref>, in some embodiments, the forward face <b>156</b> may generally follow a contour of the channel <b>134</b> and may be substantially parallel thererto. For example, the forward face <b>156</b> can be convexly rounded in a manner similar to the channel <b>134</b>. The body <b>104</b> can smoothly transition from the forward face <b>156</b> into depressions <b>158</b> at either side thereof, which can provide for a relatively smaller surface area of the body to which tissue might attach. The depressions <b>158</b> also can reduce the material costs associated with manufacture of the vascular access port <b>100</b>.

Various parameters of the vascular access port <b>100</b> can be adjusted or selected to achieve a desired performance. For example, with reference to <figref idref="DRAWINGS">FIG. 3</figref>, a maximum width WF of the funnel region <b>132</b> can be greater than a maximum width WB of the base <b>102</b>. Such an arrangement may be desirable where the vascular access port <b>100</b> is configured to be coupled with a relatively small vessel, or where a relatively large target area otherwise is desired. In various embodiments, the width WF is no less than about 1.0, 1.25, 1.50, 1.75, or 2.0 times the value of the width WB.

In some embodiments, the width WB of the base <b>102</b> can be approximately the same as or smaller than a width of a vessel to which the vascular access port <b>100</b> is configured to be attached. In various embodiments, the width WB of the base <b>102</b> can be no less than about 6, 7, 8, 9, 10, 11 or 12 millimeters, or can be no more than about 6, 7, 8, 9, 10, 11, or 12 millimeters.

In some embodiments, a height H of the vascular access port <b>100</b> can be adjusted or selected depending on the depth at which the port <b>100</b> is to be implanted within the patient. For example, some embodiments of the vascular access port <b>100</b> may be well-suited for use with a shallow vessel, such as a vein associated with an arteriovenous fistula in a forearm, whereas other embodiments may be well-suited for use with deeper vessels, such as the basilic vein in the upper arm. The depth at which the port <b>100</b> is located beneath a surface of the skin of the patient also can vary from patient to patient due to differences in anatomy. Sites at which various embodiments of the vascular access port <b>100</b> can be implanted include the cephalic, basilic, femoral, jugular, subclavian, or other suitable veins; arteries; fistulas; the stomach; other organs; or, more generally, any suitable structure where a walled membrane encircles or encapsulates a region.

In some embodiments, it can be desirable for an implanted vascular access port <b>100</b> to be beneath the surface of the skin of a patient by a sufficient amount to prevent tissue erosion, yet not so deep that palpation of the vascular access port <b>100</b> is difficult or provides insufficient information regarding the position or orientation of the port. In various embodiments, a minimum distance between a surface of the skin of a patient and an implanted port is no more than about 3, 4, 5, or 6 millimeters, is no less than about 3, 4, 5, or 6 millimeters, or is about 3, 4, 5, or 6 millimeters.

The height H can be defined as a minimum distance between the pinnacle region <b>122</b> and the bottom surface <b>108</b> of the base <b>102</b>, and the height H can be selected, adjusted, or otherwise configured so as to achieve a desired depth of the vascular access port <b>100</b> beneath the surface of the skin of a patient. In various embodiments, the height H can be no greater than about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 millimeters, or can be no less than about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 millimeters. In other or further embodiments, the height H can be no more than about 0.5, 0.75, 1.0, 1.5, 2.0, 2.5, 3.0, or 3.5 times the width WB of the base <b>102</b>, or can be no less than about 0.5, 0.75, 1.0, 1.5, or 2.0, 2.5, 3.0, or 3.5 times the width WB of the base <b>102</b>. In other or further embodiments, the angle α, as defined above, can vary with the height H. For example, in some embodiments, the angle α increases with increasing height H.

It will be appreciated that various features of the embodiments of the vascular access port <b>100</b> discussed above can be altered or modified. For example, in some embodiments, the base <b>102</b> and the body <b>104</b> comprise separate pieces that are joined to each other. For example, the base <b>102</b> may comprise a relatively compliant material that can readily change shape so as to conform to a surface of a vessel, while at least a portion of the body <b>104</b> (e.g., the funnel region <b>132</b>) can comprise a relatively rigid material. In other or further embodiments, the cavity <b>110</b> defined by the base <b>102</b> can be sized to receive any portion of a circumference of a vessel therein. Different sizes and configurations of the guidance passageway <b>130</b> are also possible, as further discussed below.

The vascular access port <b>100</b> can be implanted in a patient and used in any suitable methods. As mentioned above, it can be desirable to secure the vascular access port <b>100</b> to a vessel in such a manner that the bottom opening <b>150</b> defined by the guidance passageway <b>130</b> is fixed relative to the vessel, which can allow the guidance passageway <b>130</b> and/or the opening <b>150</b> to repeatedly direct an access device to the same portion of the vessel.

<figref idref="DRAWINGS">FIG. 8</figref> depicts an example of one such arrangement. The vascular access port <b>100</b> is fixedly and directly secured to a vessel <b>200</b>, which comprises three layers: the tunica adventita (or adventitia) layer <b>202</b>, the tunica media (or media) layer <b>204</b>, and the tunica intima (or intima) layer <b>206</b>. The term “direct,” when used herein with reference to securing or attaching a vascular access port <b>100</b> to the vessel <b>200</b>, means that some portion of the vascular access port <b>100</b> is in abutting contact with the vessel <b>200</b> and is fixedly attached thereto. In the illustrated embodiment, an attachment device <b>116</b> comprises a running suture that extends through each attachment passage <b>114</b> of the vascular access port <b>100</b>. One or more loops of the suture can extend through all three layers <b>202</b>, <b>204</b>, <b>206</b> of the vessel <b>200</b>.

In certain embodiments, it can be desirable to ensure that one or more attachment devices <b>116</b> extend through more layers of the vessel <b>200</b> than just the adventitia layer <b>202</b> (or a portion thereof), or stated otherwise, through the media and/or the intima layers <b>204</b>, <b>206</b>. For example, it has been found that attachment of certain ports solely to the adventitia layer <b>202</b> (i.e., without attachment to other tissues) can result in mobility of the ports relative to the media and intima layers <b>204</b>, <b>206</b>. The ports may shift longitudinally and/or laterally relative to the inner layers <b>204</b>, <b>206</b> of the vessel <b>200</b> from such activities as palpation of the ports during cannulation procedures or various day-to-day occurrences. Such mobility of a vascular access port can potentially result in the creation of multiple puncture sites in the vessel <b>200</b> over the course of repeated cannulations, which can weaken the vessel wall over time and potentially result in an aneurysm, vessel stenosis, hematoma, and/or bleeding.

<figref idref="DRAWINGS">FIGS. 9A-9E</figref> depict various stages of an illustrative method for implanting a vascular access port <b>100</b> in a patient <b>210</b> such that the vascular access port <b>100</b> provides direct access to a vessel within the patient <b>210</b>. The term “patient” is used broadly herein and includes any animal subject who can or does undergo some process or procedure, whether provided by another or self-administered, and the term is not limited to an individual within a healthcare facility. The vascular access port <b>100</b> may be used with any suitable vessel, such as an artery <b>212</b>, a vein <b>214</b> (both shown in <figref idref="DRAWINGS">FIG. 9A</figref>), or an artificial graft (see <figref idref="DRAWINGS">FIG. 14B</figref>). As previously discussed, the vessel may be at any of a variety of positions within the patient <b>210</b>, such as the neck, the upper arm, the forearm, or the leg, and it may be located at a relatively deep or shallow position relative to the skin <b>216</b> of the patient. Numerous uses of an implanted port <b>100</b> are possible, including, for example, hemodialysis, chemotherapy, antibiotic therapy, total parenteral nutrition, pain management, aquapheresis, plasmapheresis, hydration, or long-term therapies of any suitable variety. In the illustrated method, a vascular access port <b>100</b> is shown being implanted in a forearm of the patient <b>210</b>—specifically, the vascular access port <b>100</b> is shown being connected to a vein <b>214</b> that is associated with an arteriovenous fistula <b>218</b> for use in hemodialysis. It is noted that the vein <b>214</b> is a three-layered vessel such as the vessel <b>200</b> depicted in <figref idref="DRAWINGS">FIG. 8</figref>, and thus may be referred to hereafter as a vessel <b>200</b> to illustrate the more general applicability of the procedures discussed.

With reference to <figref idref="DRAWINGS">FIG. 9A</figref>, an incision <b>220</b> can be made in the skin <b>216</b> of the patient <b>210</b>. In the illustrated embodiment, the incision <b>220</b> can be from about 4 centimeters to about 5 centimeters in length. The incision <b>220</b> can extend substantially parallel to the vessel <b>200</b>, but can be offset relative thereto (i.e., is not directly over the vessel <b>200</b>). In the illustrated embodiment, the incision <b>220</b> is offset from a position directly over the vessel <b>200</b> by a distance of from about 2 centimeters to about 3 centimeters. As discussed further with respect to <figref idref="DRAWINGS">FIG. 9E</figref>, such an orientation of the incision <b>220</b> can facilitate access to the vascular access port <b>100</b> after the implantation procedure is complete. In other methods, the incision <b>220</b> can be directly over the vessel <b>200</b> and/or at an angle or entirely transverse relative thereto. The incision <b>220</b> can be made by a practitioner <b>224</b> using any suitable techniques and instruments.

With reference to <figref idref="DRAWINGS">FIG. 9B</figref>, the vessel <b>200</b> can be exposed by removing, partially removing, or separating skin, fat, and fascial layers from the adventitia layer <b>202</b> of the vessel <b>200</b> at the site of the incision <b>220</b>. Exposure of the vessel <b>200</b> can be maintained in any suitable manner, such as by the use of tissue spreaders <b>230</b>.

With reference to <figref idref="DRAWINGS">FIG. 9C</figref>, an initial attachment of the vascular access port <b>100</b> to the vessel <b>200</b> can be achieved at the front end or the back end of the vascular access port <b>100</b>. In some procedures, an attachment device <b>116</b> can be inserted through all three layers <b>202</b>, <b>204</b>, <b>206</b> (see <figref idref="DRAWINGS">FIG. 8</figref>) of the vessel <b>200</b> and through an attachment passage <b>114</b> at each of the front and back ends of the vascular access port <b>100</b> along a lateral center of the port <b>100</b> prior to use of any of the remaining attachment passages <b>114</b>. Initial attachment of the front end and/or the back end of the vascular access port <b>100</b> can assist in ensuring that a desired orientation of the vascular access port <b>100</b> is achieved and maintained during the course of the implantation procedure.

As previously mentioned, any suitable attachment device (or devices) <b>116</b> may be used in securing the vascular access port <b>100</b> to the vessel <b>200</b>. The attachment devices <b>116</b> can include, for example, one or more sutures, pinch rings, hooks, or wires. Once an attachment device <b>116</b> is in a desired position, it can be securely tied, crimped, twisted, or otherwise fastened.

In the illustrated embodiment, the attachment device <b>116</b> comprises a running suture, which can be looped through multiple attachment passages <b>114</b>. In the illustrated embodiment, a single running suture <b>116</b> is used to secure the vascular access port <b>100</b> to the vessel <b>200</b>. In other embodiments, the suture <b>116</b> may extend through fewer passages <b>114</b> and one or more additional sutures <b>116</b> may be used. For example, as previously discussed, in some embodiments, a separate suture <b>116</b> is secured at each end of the vascular access port <b>100</b> prior to providing sutures in any of the remaining attachment passages <b>114</b>.

Various options are available for securing one or more sutures <b>116</b> in place. For example, in some procedures, a suture needle <b>232</b> can be inserted through the wall of the vessel <b>200</b> at a position near an attachment passage <b>114</b>, and can then pass through the attachment passage <b>114</b> after having passed through the vessel wall. A suture <b>116</b> associated with the suture needle <b>232</b> can then be tied using a surgical knot and the excess suture trimmed. In other procedures, a suture <b>116</b> can be positioned at a desired location within the wall of the vessel <b>200</b> such that at least one leg thereof protrudes from the adventitia layer <b>202</b>. The protruding leg of the suture <b>116</b> can be received through a desired attachment passage <b>114</b> of the vascular access port <b>100</b> as the port <b>100</b> is brought into contact with the vessel <b>200</b>. The suture <b>116</b> can then be tied and trimmed. Either approach may be used to secure sutures <b>116</b> through any desired number of attachment passages <b>114</b> of the vascular access port <b>100</b>. Any other suitable suturing or attachment technique may be used. In some embodiments, only a portion of the available attachment passages <b>114</b> are used.

With reference to <figref idref="DRAWINGS">FIG. 9D</figref>, additional sutures <b>116</b> can be used to secure the vascular access port <b>100</b> to the vessel <b>200</b> via any or all of the remaining attachment passages <b>114</b>, as desired. In some embodiments, the attachment passages <b>114</b> are filled, such as with silicone, so as to prevent ingrowth of tissue. In other embodiments, the attachment passages <b>114</b> are left open, which can permit ingrowth of tissue therein or therethrough.

With reference <figref idref="DRAWINGS">FIG. 9E</figref>, the site of the incision <b>220</b> can be closed in any suitable manner, such as, for example, via one or more sutures <b>234</b>. As previously mentioned, the incision <b>220</b> can be offset from a position that is directly above the vascular access port <b>100</b>. In such arrangements, an access device <b>144</b> can be inserted through the skin <b>216</b> to the vascular access port <b>100</b> via a surface insertion site <b>236</b> with little or no interaction with the site of the incision <b>220</b>, or stated otherwise, without contacting any or much scar tissue at or beneath the surface of the skin <b>216</b>. In certain cases, this may assist in the creation of an insertion tract that extends from the surface insertion site <b>236</b> to the vascular access port <b>100</b>, as discussed further below.

In certain embodiments, it can be desirable to wait for a period of days or weeks after implantation of the vascular access port <b>100</b> before accessing the vessel <b>200</b> thereby. The waiting period can provide sufficient time for tissue ingrowth at the appropriate areas of the vascular access port <b>100</b>, which can provide a more secure connection between the vascular access port <b>100</b> and the vessel <b>200</b>.

<figref idref="DRAWINGS">FIGS. 10A-10G</figref> depict various stages of another illustrative method for implanting a vascular access port <b>100</b> in the patient <b>210</b> such that the vascular access port <b>100</b> provides direct access to the vessel <b>200</b> within the patient <b>210</b>. Although the methods shown in <figref idref="DRAWINGS">FIGS. 9A-9E and 10A-10G</figref> are depicted relative to the same site within the patient <b>210</b>, it is to be understood that the methods also may be used at other sites.

With reference to <figref idref="DRAWINGS">FIG. 10A</figref>, an incision <b>220</b> can be made in the skin <b>216</b> of the patient <b>210</b>, which in some embodiments can be from about 4 centimeters to about 5 centimeters in length. The incision <b>220</b> can extend substantially parallel to vessel <b>200</b> and can be offset relative thereto. In some embodiments, the offset can be by a distance of from about 2 centimeters to about 3 centimeters.

With reference to <figref idref="DRAWINGS">FIG. 10B</figref>, the vessel <b>200</b> can be exposed by removing, partially removing, or separating skin, fat, and fascial layers from the adventitia layer <b>202</b> of the vessel <b>200</b> at the site of the incision <b>220</b>. In some cases, a hemostat <b>240</b> can assist in this process. Exposure of the vessel <b>200</b> can be maintained in any suitable manner, such as by the use of tissue spreaders <b>230</b>.

With reference to <figref idref="DRAWINGS">FIG. 10C</figref>, a portion of the adventitia <b>202</b> can be isolated or separated from other portions of the vessel <b>200</b> in any suitable manner, such as via one or more forceps <b>242</b>. Each set of forceps <b>242</b> can be used to capture or gather up a portion of the adventitia <b>202</b> and/or fascia layers or fat that may not have been removed or spread apart by the tissue spreaders <b>230</b>.

With reference to <figref idref="DRAWINGS">FIG. 10C</figref>, while the portion of adventitia <b>202</b> is being held in its separated state, a small incision <b>244</b> can be made therein in any suitable manner, such as via a scalpel or via scissors <b>246</b>.

With reference to <figref idref="DRAWINGS">FIG. 10D</figref>, a hemostat <b>240</b> can be inserted through the incision <b>244</b> so as to slide between the isolated adventitia <b>202</b> and the remaining layers of the vessel <b>200</b>. In instances, it can be difficult to separate all of the adventitia <b>202</b> from the media layer <b>204</b> of the vessel <b>200</b>. This, in the illustrated embodiment, the media layer <b>204</b> is shown, but is obscured by a thin layer of adventitia <b>202</b>. The hemostat <b>240</b> can be used to bluntly dilate a pocket <b>248</b> within the adventitia <b>202</b> layer. Although not depicted, in some cases, the forceps <b>242</b> may be used to maintain control of the adventitia <b>202</b> during formation of the pocket <b>248</b>.

In certain embodiments, the pocket <b>248</b> can be sufficiently large to receive the vascular access port <b>100</b> therein, while in others, the pocket <b>248</b> can be slightly smaller than the vascular access port <b>100</b>. In some embodiments, the pocket <b>248</b> can have a length of no more than about 2.0, 2.5, 3.0, or 3.5 centimeters, and can have a width of no more than about 70, 80, or 90 percent of a width of the outer diameter of the media layer <b>204</b>.

With reference to <figref idref="DRAWINGS">FIG. 10E</figref>, the vascular access port <b>100</b> can be inserted through the incision <b>244</b> into the pocket <b>248</b>. In some cases, the forceps <b>242</b> or other clamping devices are used to maintain control of the adventitia <b>202</b> during insertion of the vascular access port <b>100</b>. The vascular access port <b>100</b> can be introduced into the pocket <b>248</b> either rearward end first, as shown, or forward end first, and the port <b>100</b> can be pushed to the end of the pocket <b>248</b> opposite the incision <b>244</b>.

With reference to <figref idref="DRAWINGS">FIG. 10F</figref>, the adventitia <b>202</b> can cover all or substantially all of the implanted vascular access port <b>100</b> when it is within the pocket <b>248</b>. Sutures <b>116</b> can be advanced through the adventitia <b>202</b>, through the attachment passages <b>114</b>, and through the remaining portion of the adventitia layer <b>202</b>, as well as through the entirety of the media and intima layers <b>204</b>, <b>206</b> to attach the vascular access port <b>100</b> to the vessel <b>200</b>. Suture knots thus may be tied outside of the adventitia <b>202</b>. In other embodiments, the sutures <b>116</b> do not pass through the separated portion of the adventitia <b>202</b> and may be tied prior to being covered by the adventitia <b>202</b>.

<figref idref="DRAWINGS">FIG. 10G</figref> depicts the site of the incision <b>220</b> in a closed configuration. The incision <b>220</b> can be closed in any suitable manner, such as in any of the manners described above with respect to <figref idref="DRAWINGS">FIG. 9E</figref>.

With reference again to <figref idref="DRAWINGS">FIGS. 10C-10F</figref>, in other methods, at least a portion of the adventitia <b>202</b> can be removed rather than forming the pocket <b>248</b> therein. The vascular access port <b>100</b> may be placed atop a thin layer of the adventitia <b>202</b> at a site from which the at least a portion of adventitia <b>202</b> has been removed, and sutures <b>116</b> may be directly inserted through the attachment passages <b>114</b> and through the thinned adventitia layer <b>202</b>, the media layer <b>204</b>, and the intima layer <b>206</b>. The vascular access port <b>100</b> may, at least initially, be less stable relative to the vessel <b>200</b> when it is implanted in this manner, rather than when it is inserted into the pocket <b>248</b>.

<figref idref="DRAWINGS">FIGS. 11A-11E</figref> depict various procedures that may be performed relative to an implanted vascular access port <b>100</b>. As will be discussed, the vascular access port <b>100</b> can facilitate the creation of a buttonhole. The vascular access port <b>100</b> likewise can facilitate use of the buttonhole once it is formed. These and/or other advantages of the vascular access port <b>100</b> will be apparent from the disclosure that follows.

Additionally, as previously mentioned, tissue may grow into or attach to various areas of the vascular access port <b>100</b>. For example, vessel tissue may grow into the ingrowth-inducing covering <b>152</b>. In some embodiments, skin tissue may grow into at least a portion of the guidance passageway <b>130</b>, although such ingrowth is not shown in <figref idref="DRAWINGS">FIGS. 11A-11E</figref>.

<figref idref="DRAWINGS">FIG. 11A</figref> depicts an embodiment of the vascular access port <b>100</b> that has been implanted in the patient <b>210</b> in any suitable manner, such as via the method depicted in <figref idref="DRAWINGS">FIGS. 9A-9E</figref>. The opening <b>150</b> of the guidance passageway <b>130</b> is at or adjacent to the vessel <b>200</b>. Specifically, in the illustrated embodiment, the opening <b>150</b> is at the adventitia layer <b>202</b> of the vessel <b>200</b>.

In the stage that is shown, a clinician <b>260</b> palpates the skin <b>216</b> to locate and determine the orientation of the vascular access port <b>100</b>. The term “clinician” is used broadly herein and includes any individual who conducts a process or procedure relative to an implanted access port <b>100</b>, whether that individual is the individual in whom the access port <b>100</b> is implanted (e.g., a patient) or someone else, and the term is not limited to an individual within a healthcare facility. In the illustrated embodiment, the clinician <b>260</b> is using fingers to contact the skin <b>216</b> located above the pinnacle region <b>122</b> of the palpation projection <b>146</b>. In other instances, the clinician <b>260</b> can palpate any other suitable portion of the body <b>104</b> to determine the location (e.g., depth) and orientation of the port <b>100</b>. For example, the clinician <b>260</b> may use one or more fingers and/or a thumb to contact the skin <b>216</b> that is over or beside other portions of the palpation projection <b>146</b>, or to squeeze the skin <b>216</b> that is at either side of the wings <b>140</b>. In still other or further embodiments, a clinician may visually determine a location and orientation of the port <b>100</b>. Prior or subsequent to the stage shown in <figref idref="DRAWINGS">FIG. 11A</figref>, the clinician <b>260</b> can clean a surface of the skin with any suitable antiseptic so as to reduce the risk of introducing pathogens into the bloodstream of the patient.

<figref idref="DRAWINGS">FIG. 11B</figref> illustrates an embodiment of an access device <b>144</b> directly accessing a lumen <b>262</b> of the vessel <b>200</b> via the vascular access port <b>100</b> for a first time. Although the fingers of the clinician <b>260</b> are not shown in <figref idref="DRAWINGS">FIG. 11B</figref>, the clinician <b>260</b> may continue to palpate the vascular access port <b>100</b> while inserting the access device <b>144</b> into the skin and the vascular access port <b>100</b>. This can aid in achieving a desired alignment of the access device <b>144</b> with the guidance channel <b>130</b>. The clinician <b>260</b> also may make minor adjustments to an orientation of the vascular access port <b>100</b> by applying pressure thereto.

The access device <b>144</b> can comprise any suitable device configured for fluid communication between a position outside of the skin <b>216</b> and the vessel lumen <b>262</b> when the device has been introduced into the lumen <b>262</b> via the vascular access port <b>100</b>. For example, in various embodiments, the access device <b>144</b> can comprise a needle or a catheter. In many embodiments, the access device <b>144</b> can be relatively rigid so as to be able to readily pass through the skin <b>216</b>. Accordingly, in some embodiments, the catheter may be an over-the-needle catheter.

Standard needles that are presently used in hemodialysis or other procedures may be used with embodiments of the vascular access port <b>100</b>, which may facilitate use of such ports. For example, standard protocols for making and using buttonholes in vessels via known freehand methods may be readily adapted to “device-assisted” buttonhole techniques that employ the vascular access ports <b>100</b>, and this can take place without alteration to the instruments called for by the existing protocols.

As the procedural stage depicted in <figref idref="DRAWINGS">FIG. 11B</figref> represents an initial access of the vessel lumen <b>262</b>, the access device <b>144</b> is shown as having a sharp tip, which can allow the access device <b>144</b> to more readily be inserted through the unbroken skin so as to form an insertion tract <b>264</b>, and also through an insertion site <b>266</b> of the vessel <b>200</b>. As further discussed below, however, other embodiments of an access device <b>144</b> that have blunt ends may be used after one or more access events with a sharp-ended access device <b>144</b> have occurred. For example, as discussed hereafter, a sharp access device <b>144</b> can be used for a given number of access events until a sufficiently defined insertion tract <b>264</b> has been formed through the skin of a patient, and a blunt access device <b>144</b> can be used thereafter. For example, a sharp access device <b>144</b> can be used for 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 access events; at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 access events; no more than 2, 3, 4, 5, 6, 7, 9, or access events; or within a range of from 1 to 10, from 2 to 9, from 3 to 8, or from 4 to 7 access events prior to the use of a blunt access device <b>144</b>. Use of the vascular access port <b>100</b> can allow for a small number of initial access events with a sharp-ended access device <b>144</b> before a blunt-ended access device <b>144</b> may be used, which may result from an ability of the vascular access port <b>100</b> to consistently and repeatedly direct an access device <b>144</b> to the same insertion site in a vessel.

In certain embodiments, the access device <b>144</b> can comprise a needle sized from 14 gauge to 20 gauge. As previously mentioned, the diameter and length of the channel <b>134</b> can be configured to direct the access device <b>144</b> to a specific region of the vessel <b>200</b>. This may be achieved by a relatively close fit between the channel <b>134</b> of the vascular access port <b>100</b>, which can provide for a predictable orientation at which the access device <b>144</b> will exit the channel <b>134</b> through the opening <b>150</b>. In some instances, it may be desirable for the channel <b>134</b> to be sized such that at least a small amount of space exists between an inner wall thereof and an access device <b>144</b> when the access device <b>144</b> is inserted therein. This can prevent or reduce binding of the access device <b>144</b> within the channel <b>134</b>, which may be more likely to occur if tissue has grown into at least a portion of the channel <b>134</b>. In some embodiments, a balancing or optimization may be achieved with respect to the spacing between the channel <b>134</b> and an access device <b>144</b> such that a sufficiently tight fit is achieved to allow the vascular access device <b>144</b> to be directed repeatedly to substantially the same area of the vessel <b>200</b> and to achieve hemostasis when the vascular access device <b>144</b> is inserted into the vessel <b>200</b> while inhibiting, reducing the occurrence of, or preventing binding of the vascular access device <b>144</b> within the channel <b>134</b>. In various embodiments, an inner diameter of the channel <b>134</b> is larger than an outer diameter of an access device <b>144</b> with which it is configured to be used by an amount within a range of from about 0.25 gauge to about 3.0 gauge, from about 0.5 gauge to about 2.0 gauge, from about 0.75 gauge to about 1.5 gauge, or from about 0.75 gauge to about 1.25 gauge; by an amount that is no less than about 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 1.75, 2.0, 2.5, or 3.0 gauge; or by an amount that is no greater than about 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 1.75, 2.0, 2.5, or 3.0 gauge. In some embodiments, the channel <b>134</b> is about 1 gauge larger than access devices <b>144</b> with which it is configured to be used. For example, in the illustrated embodiment, the channel <b>134</b> may be sized at approximately 14 gauge and the access device <b>144</b> can comprise a 15 gauge fistula needle.

Other configurations for the channel <b>134</b> and the access device <b>144</b> are also possible. For example, one or more of the channel <b>134</b> and the access device <b>144</b> may have geometries other than cylindrical. In certain of such embodiments, the geometries of the channel <b>134</b> and of the access device <b>144</b> may be complementary to each other, whereas in other embodiments, a cross-sectional shape of the channel <b>134</b> may be different from a cross-sectional shape of the access device <b>144</b>.

As previously mentioned, some protocols for the creation and use of buttonhole cannulation sites can require introduction of a needle into a vessel at a designated acute angle. In some embodiments, the angle α defined by the channel <b>134</b> (see <figref idref="DRAWINGS">FIG. 7</figref>) can be matched to this specified angle, and the channel <b>134</b> can constrain the access device <b>144</b> to enter the vessel <b>200</b> at the angle α, such that the vascular access port <b>100</b> can be configured for use with such protocols.

<figref idref="DRAWINGS">FIG. 11C</figref> illustrates a stage of the procedure after removal of the access device <b>144</b>. The insertion site <b>266</b> is shown in a closed state, in which it is allowed to heal. Prior to closure and healing of the insertion site <b>266</b>, however, blood <b>268</b> can be permitted to exit thereby, and may fill the guidance passageway <b>130</b> and the insertion tract <b>264</b>. The practitioner <b>260</b> can apply pressure above the vascular access port <b>100</b> to close the insertion tract <b>264</b> until bleeding subsides at the surface of the skin <b>216</b>. For example, the practitioner <b>260</b> can apply pressure while simultaneously applying a pad <b>269</b> (e.g., gauze) to the upper end of the insertion tract <b>264</b>. As previously mentioned, the entry mouth <b>136</b> of the guidance passageway <b>130</b> can be configured to assist in achieving hemostasis. For example, the entry mouth <b>136</b> may be relatively planar, and application of pressure above the entry mouth <b>136</b> can cause tissue surrounding the guidance passageway <b>130</b> to effectively seal the guidance passageway <b>130</b> about the entry mouth <b>136</b>. In some embodiments, a two-finger technique may be used to close the insertion tract <b>264</b> while applying pressure to the tissue positioned above the guidance passageway <b>130</b>. In some embodiments, pressure may be applied for a period of no more than about 5, 6, 7, 8, 9, or 10 minutes in order to achieve hemostasis.

A relatively tight attachment between the vascular access port <b>100</b> and the vessel <b>200</b>, such as may be achieved by tissue ingrowth within the attachment area AR (see <figref idref="DRAWINGS">FIG. 5</figref>) likewise can assist in reaching hemostasis. For example, tissue ingrowth about the opening <b>150</b> can inhibit or prevent blood <b>268</b> from seeping outwardly between the base <b>102</b> of the vascular access port <b>100</b> and the vessel <b>200</b>.

The procedures discussed with respect to <figref idref="DRAWINGS">FIGS. 11A-11C</figref> can be repeated multiple times. For example, with reference again to <figref idref="DRAWINGS">FIG. 11B</figref>, a second access device <b>144</b> having a sharp tip can be inserted through the insertion tract <b>264</b> toward the vascular access port <b>100</b> for a second insertion event. However, during the time between the first and second access events and/or as a result of palpation of the vascular access port <b>100</b> during the second access event, the vascular access port <b>100</b> and the vessel <b>200</b> to which it is attached may have shifted relative to the insertion tract <b>264</b> such that the channel <b>134</b> is no longer aligned with the insertion tract <b>264</b>. As the access device <b>144</b> is advanced through the insertion tract <b>264</b>, the tip of the access device <b>144</b> can contact the funnel region <b>132</b>. The funnel region <b>132</b> then can direct the tip of the access device <b>144</b> into the channel <b>134</b> as the access device <b>144</b> is further advanced through the insertion tract <b>264</b>. In some cases, this redirection of the tip of the access device <b>144</b> relative to the vascular access port <b>100</b> may urge the insertion tract <b>264</b> and the channel <b>134</b> into alignment with each other. Once the tip of the access device <b>144</b> enters the channel <b>134</b>, the channel <b>134</b> directs the tip of the access device <b>144</b> to the insertion site <b>266</b> of the vessel <b>200</b>. The vascular access port <b>100</b> thus can direct the access device <b>144</b> to the same insertion site <b>266</b> via which the vessel lumen <b>262</b> was accessed in the first access event.

<figref idref="DRAWINGS">FIG. 11D</figref> depicts the insertion tract <b>264</b> and the insertion site <b>266</b> after multiple access events. As shown, the insertion tract <b>264</b> may become more well-defined over time, which may, for example, result from the formation of scar tissue or connective tissue. Similarly, the insertion site <b>266</b> may become more well-defined over time such that it may become easier to insert an access device <b>144</b> therethrough. Such an insertion site <b>266</b> through a vessel wall can be referred to as a buttonhole access site, or more commonly, as a buttonhole. Accordingly, the insertion site <b>266</b> may also be referred to herein as a buttonhole <b>266</b>. In some embodiments, the well-defined insertion tract <b>264</b> and/or the buttonhole <b>266</b> may be established after 6, 7, 8, 9, or 10 access events.

In other embodiments, the insertion tract <b>264</b> and the buttonhole <b>266</b> can be formed by inserting an over-the-needle catheter (not shown) through the vascular access port <b>100</b>. The needle portion can be removed and the catheter portion can be left in place until the insertion tract <b>264</b> is well-defined. The catheter then can be removed.

As previously discussed, in some instances, the vascular access port <b>100</b> may shift relative to the insertion tract <b>264</b> between access events. However, in certain embodiments, the funnel region <b>132</b> of the guidance passageway <b>130</b> is sufficiently large that a distal end of the insertion tract <b>264</b> opens into, or extends through at least a portion of, the funnel region <b>132</b> despite any such shifting. Accordingly, the vascular access port <b>100</b> may act as a mobile extension of the insertion tract <b>264</b>, which is configured to ensure that access devices <b>144</b> are consistently aligned with and directed to the buttonhole <b>266</b>, despite any relative movement between the insertion tract <b>264</b> and the vascular access port <b>100</b>. In some instances, however, relatively little shifting may occur between the insertion tract <b>264</b> and the vascular access port <b>100</b>, and an access device <b>144</b> may be inserted through the insertion tract <b>264</b> and directly into the channel <b>134</b> with little or no contact with the funnel region <b>132</b>.

<figref idref="DRAWINGS">FIG. 11D</figref> also illustrates that a scab <b>270</b> may form over the insertion tract <b>264</b> between access events. The scab <b>270</b> may be removed prior to an access event. In other embodiments, a synthetic covering may be provided over or in place of the scab <b>270</b>.

<figref idref="DRAWINGS">FIG. 11E</figref> illustrates the use of an access device <b>144</b> having a blunt distal end after proper formation of the insertion tract <b>264</b> and the buttonhole <b>266</b>. The blunt end of the access device <b>144</b> can guide the device <b>144</b> through the insertion tract <b>264</b> and through the buttonhole <b>266</b>, and may do so in a less traumatic or more comfortable manner for the patient <b>210</b>. Use of a blunt-tipped access device <b>144</b> also can reduce the risk of striking through an opposing side of the vessel <b>200</b>.

As previously mentioned, in some embodiments, an over-the needle catheter can be used with an implanted vascular access port <b>100</b>. In certain procedures, a needle/catheter assembly can be inserted through the insertion tract <b>264</b> into the vessel <b>200</b> (e.g., the jugular vein) and then the catheter can be advanced through the vessel to the desired position (e.g., the superior vena cava for certain central venous system applications). An infusion or other desired procedure can then be conducted. The catheter can be removed from the patient after completion of the procedure.

<figref idref="DRAWINGS">FIG. 12</figref> depicts an embodiment of the vascular access port <b>100</b> that has been implanted in the patient <b>210</b> via a method such as that depicted in <figref idref="DRAWINGS">FIGS. 10A-10G</figref>. A portion of the adventitia layer <b>202</b> of the vessel <b>200</b> thus extends over the vascular access port <b>100</b>. Accordingly, when an access device <b>144</b> is inserted into the vessel <b>200</b> via the access port <b>100</b>, it passes through the adventitia layer <b>202</b> before entering the vascular access port <b>100</b>. Otherwise, procedures for creating and using buttonholes can be similar to those described above with respect to <figref idref="DRAWINGS">FIGS. 11A-11E</figref>.

<figref idref="DRAWINGS">FIG. 13</figref> depicts an illustrative example of an embodiment of a buttonhole access site <b>266</b> in a vessel <b>200</b> that was formed by repeated insertion of access devices <b>144</b> through an embodiment of a vascular access port <b>100</b>. <figref idref="DRAWINGS">FIG. 13</figref> is a photograph of a filleted portion of the vessel <b>200</b>, and is shown from a bottom plan view thereof (i.e., a view directed toward the intima layer <b>206</b>). A contour of the vascular access port <b>100</b> is visible in the photograph, as are portions of a running suture <b>116</b> that extend through the initima layer <b>206</b>.

In this particular example, the vascular access port <b>100</b> was implanted in a sheep for a period of 9 weeks. After a waiting period to permit for tissue ingrowth, a sharp needle was inserted through the vascular access port <b>100</b> to access the vessel <b>200</b>. Six (6) additional access events were conducted thereafter using a sharp needle, followed by twelve (12) access events using a blunt needle. Accordingly, a total of nineteen (19) cannulations were performed. The access events were conducted at a frequency of three per week.

<figref idref="DRAWINGS">FIG. 14A</figref> depicts an embodiment of a hemodialysis system <b>300</b> that includes two vascular access ports <b>100</b>A, <b>100</b>B. Both of the ports <b>100</b>A, <b>100</b>B are shown attached to a vessel <b>200</b> that is associated with an arteriovenous fistula <b>218</b>. One port <b>100</b>A is directed upstream such that a forward end thereof points in a direction opposite to the flow of blood through the vessel <b>200</b>, and the other port <b>100</b>B is directed downstream such that a forward end thereof points in the direction of the blood flow through the vessel <b>200</b>. A fistula needle may be introduced into each of the ports <b>100</b>A, <b>100</b>B and hemodialysis performed. The first port <b>100</b>A can be an uptake port through which blood is removed from the vessel <b>200</b> and delivered to a hemodialysis machine, and the second port <b>100</b>B can be a return port through which filtered blood is returned to the vessel <b>200</b> from the hemodialysis machine.

In other embodiments, the hemodialysis system <b>300</b> can comprise only a single vascular access port <b>100</b>A or <b>100</b>B. Hemodialysis may be conducted thereby via any suitable method, such as a single-needle hemodialysis technique.

In still other embodiments, the hemodialysis system <b>300</b> includes more than two vascular access ports <b>100</b>A, <b>100</b>B. A clinician thus can rotate among the ports <b>100</b>A, <b>100</b>B, thereby leaving one or more of the ports unused during any given hemodialysis session.

<figref idref="DRAWINGS">FIG. 14B</figref> depicts another embodiment of a hemodialysis system <b>350</b>. The illustrated embodiment includes two vascular access ports <b>100</b>A, <b>100</b>B, but more or fewer ports are possible. Both of the ports <b>100</b>A, <b>100</b>B are shown attached to an artificial graft vessel <b>352</b> that serves as a shunt between an artery <b>212</b> and a vein <b>214</b>. The graft vessel <b>352</b> can comprise any suitable material, such as e-PTFE. The ports <b>100</b>A, <b>100</b>B can be attached to the graft vessel <b>352</b> prior to its implantation, or may be attached to the graft vessel <b>352</b> after it has been implanted. The hemodialysis system <b>350</b> can function similarly to the system <b>300</b> described above, with the port <b>100</b>A serving as an uptake port and the port <b>100</b>B serving as a return port.

<figref idref="DRAWINGS">FIGS. 15-17</figref> illustrate another embodiment of a vascular access port <b>400</b>, which can resemble the vascular access port <b>100</b> described above in certain respects. Accordingly, like features are designated with like reference numerals, with the leading digits incremented to “4.” Relevant disclosure set forth above regarding similarly identified features thus may not be repeated hereafter. Moreover, specific features of the vascular access port <b>400</b> may not be shown or identified by a reference numeral in the drawings or specifically discussed in the written description that follows. However, such features may clearly be the same, or substantially the same, as features depicted in other embodiments and/or described with respect to such embodiments. Accordingly, the relevant descriptions of such features apply equally to the features of the vascular access port <b>400</b>. Any suitable combination of the features and variations of the same described with respect to the vascular access port <b>100</b> can be employed with the vascular access port <b>400</b>, and vice versa. This pattern of disclosure applies equally to further embodiments depicted in subsequent figures and described hereafter.

Moreover, additional embodiments of vascular access ports are described in U.S. patent application Ser. No. 12/697,167, titled VASCULAR ACCESS PORTS AND RELATED SYSTEMS AND METHODS, filed Jan. 29, 2010, published as U.S. Patent Application Publication No. 2010/0191179. The entire contents of the foregoing application are hereby incorporated by reference herein. Any suitable combination of the features and variations of the same described with respect to the vascular access ports of the present disclosure can be employed with the vascular access ports set forth in the aforementioned co-pending U.S. Patent application and publication, and vice versa.

Furthermore, apparatus and methods for implanting embodiments of the vascular access port <b>400</b> are described below. Additional apparatus and methods that may suitably be used for this purpose are described in co-pending U.S. patent application Ser. No. 12/480,678, titled TISSUE MANAGEMENT METHODS, APPARATUS, AND SYSTEMS, which was filed on Jun. 8, 2009 and published as U.S. Patent Application Publication No. 2010/0121358. The entire contents of the foregoing application are hereby incorporated by reference herein. Any suitable combination of the features and variations of the same described with respect to the implantation apparatus and methods of the present disclosure can be employed with the implantation apparatus and methods set forth in U.S. patent application Ser. No. 12/480,678, and vice versa.

The vascular access port <b>400</b> can include a base <b>402</b> and a body <b>404</b> that extends away from the base <b>402</b>. The base <b>402</b> is elongated in a longitudinal direction. In particular, the illustrated base <b>402</b> defines a substantially rectangular perimeter <b>406</b> that extends a greater distance in a longitudinal direction than it does in a transverse direction. The edges and corners of the rectangular perimeter <b>106</b> can be rounded, which can prevent trauma to surrounding tissue when the vascular access port <b>400</b> is implanted.

The base <b>402</b> can include a base surface or bottom surface <b>408</b> that is configured to face a vessel when the vascular access port <b>400</b> is coupled to the vessel. The bottom surface <b>408</b> is described further below. An outer surface <b>407</b> of the body <b>404</b> can extend upwardly from the base <b>402</b>. In particular, the outer surface <b>407</b> may extend upwardly from the perimeter <b>406</b> of the base <b>402</b>. In the illustrated embodiment, the outer surface <b>407</b> is substantially perpendicular to a plane defined by the bottom surface <b>408</b>. The body <b>404</b> can terminate at an uppermost end thereof at a pinnacle region <b>422</b>. In the illustrated embodiment, the pinnacle region <b>422</b> defines a plane, which can be substantially parallel to the plane defined by the bottom surface <b>408</b>.

The vascular access port <b>400</b> can include a guidance passageway <b>430</b>, which can resemble the guidance passageway <b>130</b> described above. The guidance passageway <b>430</b> can include an entry mouth <b>436</b> at a proximal end thereof, a funnel region <b>432</b>, a channel <b>434</b>, and a distal opening <b>450</b>. The funnel region <b>432</b> can narrow from the entry mouth <b>436</b> toward the channel <b>434</b> so as to guide an access device <b>144</b> toward the channel <b>434</b>. The entry mouth <b>436</b> can be configured to assist in achieving hemostasis, such as in the manners described above. For example, in the illustrated embodiment, the entry mouth <b>436</b> is substantially planar (see <figref idref="DRAWINGS">FIG. 16</figref>). The channel <b>434</b> can define an angle relative to the bottom surface <b>408</b>. For example, a central or longitudinal axis of the channel <b>434</b> can define any of the angles α described above.

The funnel region <b>432</b> can include a base surface <b>438</b> that projects rearwardly from the channel <b>434</b> and that narrows in the rearward direction. As shown in <figref idref="DRAWINGS">FIG. 16</figref>, the base surface <b>138</b> of the funnel region <b>432</b> can be angled slightly upwardly (in a rearward direction) relative to the bottom surface <b>408</b> of the base <b>402</b>. The funnel region <b>432</b> also can include a backstop portion <b>442</b> similar to the backstop portion <b>142</b> described above, although the backstop portion <b>442</b> is more angled relative to the vertical.

The body <b>404</b> can include two palpation projections or ridges <b>446</b>, <b>447</b>, which can be oriented substantially transversely. The palpation projections <b>446</b>, <b>447</b> can be spaced from each other by a recess <b>449</b> that also runs in a substantially transverse direction. A seal or sealing device <b>460</b> can be received within the recess <b>449</b> when in a closed state, as shown. The palpation projections <b>446</b>, <b>447</b> thus can act as a barrier to the sealing device <b>460</b> when it is closed, which can inhibit, reduce, or prevent surrounding tissue from moving over, moving against, or otherwise interfering with the sealing device <b>460</b> when the vascular access port <b>400</b> is implanted in a patient, such as may occur via ordinary events (e.g., movement or bumping of the implantation site by a patient) or via intentional palpation of one or more of the palpation projections <b>446</b>, <b>447</b>.

The sealing device <b>460</b> can be configured to transition from an open state to a closed state, and can seal a portion of the vascular access port <b>400</b> when in the closed state. The sealing device <b>460</b> can include any suitable closure device, such as, for example, one or more doors, ports, or flaps <b>461</b>. In the illustrated embodiment, the flaps <b>461</b> are fixedly attached to the vascular access port <b>400</b> at one end thereof and are able to move relative to the port <b>400</b> at an opposite end thereof. In some embodiments, a portion of a flap <b>461</b> can be integrally formed with the port <b>400</b>, or the flap <b>461</b> can be formed as separate piece of which a portion is attached to the port <b>400</b> via any suitable method (e.g., adhesives, fasteners, welds, etc.). In the illustrated embodiment, each of the outer ends of the flaps <b>461</b> is attached to the body <b>404</b> of the port <b>400</b> via an anchoring device <b>462</b>, which includes a laser-welded titanium band.

In the illustrated embodiment, each flap <b>461</b> is configured to rotate about a hinge region at or adjacent to the anchoring device <b>462</b>. For example, the flaps <b>461</b> can comprise a shape memory alloy (e.g., nickel titanium) or some other resilient material having a natural state that corresponds with the closed state illustrated in <figref idref="DRAWINGS">FIGS. 15 and 16</figref>. Accordingly, as discussed further below, the flaps <b>461</b> can be held in an open position to permit implantation devices to extend through the vascular access port <b>400</b> during an implantation procedure, and upon removal of the implantation devices, the flaps <b>461</b> can return to their natural or closed state.

When in the closed state, the one or more flaps <b>461</b> can seal an upper end of the body <b>404</b>. For example, in the illustrated embodiment, the inner edges of the flaps <b>461</b> create a substantially fluid-tight seal with each other and bottom surfaces of the flaps <b>461</b> create a substantially fluid-tight seal with a portion of the body <b>404</b> that defines a base wall of the recess <b>449</b>. Other suitable arrangements for sealing the vascular access port <b>400</b> are also possible.

With reference to <figref idref="DRAWINGS">FIGS. 16 and 17</figref>, the vascular access port <b>400</b> can define an implantation passageway or primary passageway <b>464</b>, which can extend through both the base <b>402</b> and the body <b>404</b>. In the illustrated embodiment, a longitudinal axis of the primary passageway <b>464</b> is substantially perpendicular a plane defined by the bottom surface <b>408</b>. In other embodiments, a longitudinal axis of the primary passageway <b>464</b> can be at a non-perpendicular angle (e.g., an acute angle) relative to the bottom surface <b>408</b>.

The primary passageway <b>464</b> and the guidance passageway <b>430</b> can be connected to each other. For example, in the illustrated embodiment, the guidance passageway <b>430</b> is joined with the primary passageway <b>464</b> in a substantially y-shaped configuration in which the guidance passageway <b>430</b> terminates at the primary passageway <b>464</b>. Stated otherwise, the primary passageway <b>464</b> and the guidance passageway <b>430</b> can be in fluid communication with each other via the opening <b>450</b>. In the illustrated embodiment, the channel <b>434</b> is spaced from the bottom surface <b>408</b> of the port <b>400</b> and is configured to direct an access device <b>144</b> into the primary passageway <b>464</b> via the opening <b>450</b>, which is positioned in a sidewall that defines the primary passageway <b>464</b>. The primary passageway <b>464</b> can have a lower opening <b>466</b>, which can be positioned at the bottom surface <b>408</b>, and an upper opening <b>468</b>, which can be selectively sealed by the flaps <b>461</b> as described above.

In other embodiments, the guidance passageway <b>430</b> can be joined with the primary passageway <b>464</b> in a substantially x-shaped configuration in which the guidance passageway <b>430</b> intersects and extends through the primary passageway <b>464</b>. In certain of such embodiments, multiple openings may extend through the bottom surface <b>408</b> of the vascular access port <b>400</b>; for example, the lower opening <b>466</b> of the primary passageway <b>464</b> and a distal opening of the guidance passageway <b>430</b> each can extend through the bottom surface <b>408</b> of the vascular access port <b>400</b> at a different position. In still other embodiments, the guidance passageway <b>430</b> may be fully separate from the primary passageway <b>464</b>, and each passageway <b>430</b>, <b>464</b> can define a separate opening in the bottom surface <b>408</b> of the vascular access port <b>400</b>. Other arrangements of the passageways <b>430</b>, <b>464</b> are also contemplated.

The primary passageway <b>464</b> can include a tissue ingrowth region <b>469</b>. In the illustrated embodiment, the ingrowth region <b>469</b> comprises a recessed groove that can be covered with any suitable ingrowth-inducing covering <b>152</b>. In the illustrated embodiment, the ingrowth region <b>469</b> is recessed relative to an inner wall that defines the primary passageway <b>464</b>. Such an arrangement can facilitate insertion and removal of components of the implantation assembly <b>500</b> through the primary passageway <b>464</b> and/or otherwise inhibit or prevent interaction between the ingrowth-inducing covering <b>152</b> and the components during their insertion and removal.

With continued reference to <figref idref="DRAWINGS">FIGS. 16 and 17</figref>, the bottom surface <b>408</b> can extend inwardly from the perimeter <b>406</b> of the base <b>402</b> and can terminate at the lower opening <b>466</b> of the primary passageway <b>464</b>. In the illustrated embodiment, a rearward end of the bottom surface <b>408</b> is substantially planar. In other embodiments, at least a portion of the bottom surface <b>408</b> can be bowed in a transverse direction so as to more closely conform to a surface of a vessel wall in a manner such as discussed above with respect to the bottom surface <b>108</b>.

The bottom surface <b>408</b> can include an attachment area or attachment region <b>470</b> that encompasses the bottom opening <b>466</b>. The attachment region <b>470</b> can be configured to assist in attaching the vascular access port <b>400</b> to a vessel, and can be configured to provide a hemostatic seal about the opening <b>466</b>, as discussed further below. In the illustrated embodiment, the attachment region <b>470</b> includes a plurality of outward extensions, projections, or everting members <b>472</b>. The everting members <b>472</b> can be substantially wedge-shaped, which, as discussed below, can assist in the eversion of a vessel wall. An attachment recess <b>474</b> separates each set of adjacent everting members <b>472</b> from each other.

The bottom surface <b>408</b> also can define one or more stops <b>476</b>, which can project downwardly or away from the body <b>404</b>. Additionally, one or more connection passages or connection channels <b>478</b> can extend upwardly from the bottom surface <b>408</b>. In the illustrated embodiment, the connection channels <b>478</b> extend fully through both the base <b>402</b> and the body <b>404</b> (see <figref idref="DRAWINGS">FIG. 1</figref>). The features described in the present paragraph can be configured to cooperate with an attachment clip to secure the vascular access port <b>400</b> to a vessel, as discussed hereafter.

In some embodiments, at least a portion of the bottom surface <b>408</b> includes an ingrowth-inducing covering, such as the ingrowth inducing covering <b>152</b> discussed above. In other or further embodiments, at least a portion of the body <b>404</b> can include an ingrowth-inducing covering at an exterior surface thereof.

<figref idref="DRAWINGS">FIG. 18</figref> illustrates an embodiment of a clip <b>480</b> that is compatible with the vascular access port <b>400</b>. The clip <b>480</b> can comprise any suitable material, such as, for example, stainless steel, and can be formed in any suitable manner, such as, for example, machining (e.g., electrical discharge machining), laser cutting, or progressing metal bending. The clip <b>480</b> may be referred to as an attachment device.

The clip <b>480</b> includes a base ring <b>482</b>, which is substantially circular in the present embodiment. Any suitable size and shape of the base ring <b>482</b> is contemplated. For example, in some embodiments, the base ring <b>482</b> may be oval-shaped. The size of the base ring <b>482</b> can be configured to interact in a desired manner with a vessel to which the vascular access port <b>400</b> is to be attached. For example, in some embodiments an outer diameter of the base ring <b>482</b> may be slightly larger than, no larger than, approximately the same as, or smaller than an outer diameter of the vessel with which the vascular access port <b>400</b> is configured to be coupled. The base ring <b>482</b> can define an opening <b>483</b> at an interior thereof.

The clip <b>480</b> can include a plurality of features that extend upwardly from the base ring <b>482</b>. For example, one or more connection posts <b>484</b> can project upwardly from the base ring <b>482</b>. In the illustrated embodiment, four connection posts <b>484</b> extend upwardly from an outer edge of the base ring <b>482</b>, and adjacent posts <b>484</b> are spaced from each other at 90 degree intervals. More or fewer connection posts <b>484</b> may be used, and the posts <b>484</b> may be arranged at other positions relative to each other. In the illustrated embodiment, each connection post <b>484</b> comprises two resilient prongs <b>485</b>, which can be configured to provide outwardly directed forces when flexed toward each other. In other embodiments, more than two prongs <b>485</b> may be associated with a given connection post <b>484</b>. Other arrangements for the connection posts <b>484</b> are contemplated.

One or more retention posts <b>486</b> likewise can extend from the base ring <b>482</b>. In the illustrated embodiment, the retention posts <b>486</b> project outwardly somewhat before projecting upwardly such that they are further from an axial center of the base ring <b>482</b> than are the connection posts <b>484</b>. The retention posts <b>486</b> can have tips that are angled or chamfered in multiple directions, as in the illustrated embodiment, or that are rounded or radiused, which can aid in initially inserting the clip <b>480</b> into a temporary retention device, which is discussed below. The illustrated embodiment includes three retention posts <b>486</b> that are constrained to approximately one half of the base ring <b>482</b> and that are spaced from each other by approximately 90 degrees. The portion of the base ring <b>482</b> that is devoid of retention posts <b>486</b> can be configured to be positioned adjacent to the rearward end of the vascular access device <b>400</b>, or beneath the guidance channel <b>430</b> (see, e.g., <figref idref="DRAWINGS">FIGS. 19 and 23A</figref>).

One or more grips or teeth <b>488</b> likewise can extend from the base ring <b>482</b>. In the illustrated embodiment, six teeth extend upwardly from an interior edge of the base ring <b>482</b>. Adjacent teeth <b>488</b> are spaced from each other by about 60 degrees. More or fewer teeth <b>488</b> may be used, and the teeth <b>488</b> may be arranged at other positions relative to each other.

At least a portion of the clip <b>480</b> can include an ingrowth-inducing covering <b>152</b>, which can encourage tissue ingrowth to secure the clip <b>480</b> to a wall of a vessel. In the illustrated embodiment, the ingrowth-inducing covering <b>152</b> extends over an upper surface of the base ring <b>482</b>, and also extends over a lower surface thereof (see <figref idref="DRAWINGS">FIG. 19</figref>). In other embodiments, the covering <b>152</b> may extend only over one of the upper and lower surfaces of the base ring <b>482</b>. One or more holes <b>489</b> may extend through the base ring <b>482</b> to permit tissue to grow therethrough so as to enhance the attachment of the vascular access port <b>400</b> to a vessel.

<figref idref="DRAWINGS">FIG. 19</figref> illustrates the clip <b>480</b> connected with the vascular access port <b>400</b>. The stops <b>485</b> can interact with the outward projection portions of the retention posts <b>486</b> to prevent the base ring <b>482</b> from contacting the bottom surface <b>408</b> of the vascular access port <b>400</b>. Additionally, the retention posts <b>486</b> are spaced from the body <b>404</b> of the vascular access port <b>400</b>.

The connection posts <b>484</b> are received within and frictionally engage the connection channels <b>478</b>. In some embodiments, the connection channels <b>478</b> define a substantially constant inner diameter such that the force by which the resilient prongs <b>485</b> maintain a connection between the clip <b>480</b> and the vascular access port <b>400</b> is substantially constant as the prongs <b>485</b> are advanced deeper within the connection channels <b>478</b>. In other embodiments, an inner diameter of the connection channels <b>478</b> may decrease with increasing distance from the bottom surface <b>408</b> such that the retention or connection forces increase as the prongs <b>485</b> are advanced deeper into the channels <b>478</b>.

The teeth <b>488</b> of the clip <b>400</b> are received within the attachment recesses <b>474</b> of the vascular access port <b>400</b>. In the illustrated embodiment, the attachment recesses <b>474</b> are relatively deep, narrow, and parallel to each other. The sidewalls of the attachment recess <b>474</b> may be spaced so as to allow a portion of a vessel wall to fit between them and the teeth <b>488</b> without unduly crushing or otherwise damaging the vessel wall when the clip <b>480</b> is coupled with the vascular access port <b>400</b>, as further discussed below. Accordingly, in the illustrated embodiment, the teeth <b>488</b> can cooperate with the attachment recesses <b>474</b> to capture, grip, or retain a wall of a vessel, as discussed below. In other embodiments, the sidewalls of the attachment recesses <b>474</b> may be spaced further from each other at an entry end thereof and/or may be more rounded (see, e.g., <figref idref="DRAWINGS">FIG. 25</figref>). In still other embodiments, there may be less or even no spacing between the teeth <b>488</b> and the sidewalls of the attachment recesses <b>474</b>, and/or the teeth <b>488</b> can be configured to puncture the vessel wall when the teeth <b>488</b> are received within the attachment recesses <b>474</b>.

<figref idref="DRAWINGS">FIGS. 20 and 21</figref> illustrate an embodiment of a percutaneous implantation assembly <b>500</b> that can be used to implant the vascular access port <b>400</b> within a patient. The implantation assembly <b>500</b> can resemble devices described in U.S. patent Ser. No. 12/480,678, titled TISSUE MANAGEMENT METHODS, APPARATUS, AND SYSTEMS. As shown in <figref idref="DRAWINGS">FIG. 20</figref>, the implantation assembly <b>500</b> can generally include an insertion portion <b>502</b> that is configured to be inserted through a vessel wall and also to capture the vessel wall, a tract dilation portion <b>504</b> that is configured to open a tract through the skin of a patient through which the vascular access port <b>400</b> can be advanced into proximity to the vessel wall, and a control portion <b>506</b> that remains outside of the patient during the implantation procedure and that is used by a practitioner to activate different functionalities of the implantation assembly <b>500</b>. With reference to <figref idref="DRAWINGS">FIG. 21</figref>, the implantation assembly <b>500</b> can include one or more mechanical actuators <b>512</b> and/or one or more hydraulic or pneumatic actuators <b>514</b> via which movement of various components of the implantation assembly <b>500</b> relative to each other can be achieved.

With reference to <figref idref="DRAWINGS">FIGS. 21 and 22A</figref>, the implantation assembly <b>500</b> can include a flexible introducer tip <b>520</b> that is configured to be inserted into the lumen of a vessel <b>200</b>. The introducer tip <b>520</b> can be flexible so as to readily deform to follow a lumen the blood vessel <b>200</b> once inserted therein, and it can be substantially atraumatic to an inner surface of an inner surface of the <b>200</b> so as to be able to follow the inner surface substantially without imparting damage thereto. For example, in various embodiments, the introducer tip <b>520</b> can comprise a flexible material such as polyurethane, thermoplastic elastomer, or silicone rubber. The introducer tip <b>520</b> can define at least a portion of a lumen <b>521</b> (<figref idref="DRAWINGS">FIG. 22A</figref>) of the implantation assembly <b>500</b> through which a guidewire (not shown) may pass. Accordingly, in some embodiments, the introducer tip <b>520</b> can be inserted into the blood vessel <b>200</b> over the guidewire, and may bend or otherwise deform to follow a contour of the guidewire and/or a contour of the wall of the vessel <b>200</b>.

In certain embodiments, at least a portion of the introducer tip <b>520</b> is radiopaque. For example, in various embodiments, the introducer tip <b>520</b> can comprise one or more radiopaque agents such as barium sulfate, bismuth trioxide, titanium dioxide, or the like. In other or further embodiments, the introducer tip <b>520</b> can be coated with a lubricious coating, such as a hydrophilic polymer, silicone oil, or other suitable lubricious material. The coating can facilitate a smooth passage of the introducer tip <b>520</b> through skin tissue and through the wall of a vessel <b>200</b>.

The introducer tip <b>520</b> can be attached to an anvil <b>522</b> in any suitable manner, and the anvil <b>522</b> can be attached to an anvil pull tube <b>524</b> (<figref idref="DRAWINGS">FIG. 22A</figref>) in any suitable manner. Accordingly, movement of the anvil pull tube <b>524</b> can effect movement of the anvil <b>522</b> and of the introducer tip <b>520</b>.

With continued reference to <figref idref="DRAWINGS">FIGS. 21 and 22A</figref>, the implantation assembly <b>500</b> can include a clamp <b>526</b> that is attached to a clamp tube <b>528</b>. The clamp tube <b>528</b> and the anvil pull tube <b>524</b> can be configured to move independently from each other, when desired, such that relative movement between the anvil <b>522</b> and the clamp <b>526</b> can be achieved.

In the illustrated embodiment, a gripping ring <b>529</b> is attached to the clamp <b>526</b>, and at least a portion of the gripping ring <b>529</b> and the clamp <b>526</b> can be received within a cavity defined by the anvil <b>522</b>. The gripping ring <b>529</b> can include a plurality of teeth-like prongs that are biased radially outwardly relative to the clamp <b>526</b> such that movement of the clamp <b>526</b> and the gripping ring <b>529</b> outside of the anvil <b>522</b> allows the gripping ring <b>529</b> to expand radially outwardly so as to assist in capturing a wall of the vessel <b>200</b>, and movement of the clamp <b>526</b> and the gripping ring <b>529</b> back into the anvil <b>522</b> draws the vessel wall inward and clamps the vessel wall between the anvil <b>522</b> and the clamp <b>526</b>. The wall of the vessel <b>200</b> is shown in this clamped configuration in <figref idref="DRAWINGS">FIG. 22A</figref>. In some embodiments, at least a portion of the adventitia layer <b>202</b> and substantially a full thickness of each of the media and intima layers <b>204</b>, <b>206</b> (see <figref idref="DRAWINGS">FIG. 8</figref>) can be captured between the anvil <b>522</b> and the clamp <b>526</b>.

With reference again to <figref idref="DRAWINGS">FIG. 21</figref>, the implantation assembly <b>500</b> can include a tract dilator <b>530</b>, which can include a plurality of (e.g., three) dilation legs <b>532</b>. Once the dilation legs <b>532</b> have been inserted into the skin of a patient, they can be expanded to form an expanded implantation tract <b>280</b> (<figref idref="DRAWINGS">FIG. 22A</figref>). In various embodiments, the implantation tract <b>280</b> may be expanded prior to or after the clamping of the wall of the vessel <b>200</b>. In <figref idref="DRAWINGS">FIG. 22A</figref>, the implantation tract <b>280</b> is shown in an expanded state, but the dilation legs <b>532</b> that would encompass the components illustrated in this drawing to maintain expansion of the tract <b>280</b> are not shown so as to allow for easier identification of the illustrated components.

Once the implantation tract <b>280</b> has been expanded, an adapter tube <b>540</b>, which can include a retaining adapter <b>542</b> at a distal end thereof, can be advanced distally through the tract <b>280</b>. With reference to <figref idref="DRAWINGS">FIG. 22A</figref>, the retaining adapter <b>542</b> can include a plurality of retention channels <b>544</b>, which can cooperate with the retention prongs <b>486</b> to temporarily hold the clip <b>480</b> during implantation of the vascular access port <b>400</b>, and which can release the retention prongs <b>486</b> during a later implantation stage as discussed below. In the stage illustrated in <figref idref="DRAWINGS">FIG. 22A</figref>, the proximal tips of the connection prongs <b>484</b> of the clip <b>480</b> are within the connection channels <b>478</b> (see <figref idref="DRAWINGS">FIG. 17</figref>) of the vascular access port <b>400</b> such that the port <b>400</b> is initially attached to the retaining adapter <b>542</b> via the clip <b>480</b>.

The retaining adapter <b>542</b> can define a channel <b>546</b> through which the vascular access port <b>400</b> can move. In particular, the vascular access port <b>400</b> can initially be positioned at a proximal end of the channel <b>546</b> and can be advanced to a distal end thereof in subsequent stages of an implantation procedure, as discussed further below.

In the illustrated embodiment, the vascular access port <b>400</b> can include a temporary closure or temporary plug <b>452</b> within the channel <b>434</b>. The plug <b>452</b> can comprise a hemostatic agent, such as a resorbable material that is configured to resorb, dissolve, or otherwise vacate the channel <b>434</b> after implantation of the vascular access port <b>400</b>, as discussed further below. For example, the plug <b>452</b> can comprise any suitable material from the list of resorbable materials set forth above, collagen, plyurethane foam, etc. In some embodiments, the plug <b>452</b> comprises Surgicel®.

With continued reference to <figref idref="DRAWINGS">FIG. 22A</figref>, the implantation assembly <b>500</b> can include a push tube <b>550</b>. The push tube <b>550</b> can define one or more openings <b>552</b> through which the one or more flaps <b>461</b> can extend when they are in an open orientation.

The implantation assembly <b>500</b> can further include a cutting tube <b>560</b>. The cutting tube <b>560</b> can include a cutting blade <b>562</b> at a distal end thereof that can be sufficiently sharp to embed within a proximal surface of the anvil <b>522</b>. In the illustrated stage, the flaps <b>461</b> are in an open orientation, which permits the cutting tube <b>560</b> to extend through the primary passageway <b>464</b> of the vascular access port <b>400</b>. The presence of the cutting tube <b>560</b> within the primary passageway <b>464</b> can maintain the biased flaps <b>461</b> in the open orientation. Removal of the cutting tube <b>560</b>, and components interior thereto, from the primary passageway <b>464</b> thus can permit the flaps <b>461</b> to transition to the closed orientation (see <figref idref="DRAWINGS">FIGS. 22D and 23A</figref>).

The implantation assembly <b>500</b> can include one or more spacers <b>570</b> to maintain a desired orientation between adjacent tubes. For example, in the illustrated embodiment, a spacer <b>570</b> is attached to an interior surface of the cutting tube <b>560</b> and is configured to translate relative to an exterior surface of the clamp tube <b>528</b>. The spacer <b>570</b> can maintain the cutting tube <b>560</b> and the clamp tube <b>528</b> in a concentric orientation.

<figref idref="DRAWINGS">FIGS. 22A-22E</figref> illustrate various stages of an implantation of the vascular access port <b>400</b> using the implantation assembly <b>500</b>. As previously mentioned, a wall of the vessel <b>200</b> can be clamped between the anvil <b>520</b> and the clamp <b>526</b> and the tract dilator <b>530</b> (<figref idref="DRAWINGS">FIG. 21</figref>) can be activated so as to expand the implantation tract <b>280</b> and retain the implantation tract <b>280</b> in the expanded state. <figref idref="DRAWINGS">FIG. 22A</figref> shows the clamped wall of the vessel <b>200</b> and the expanded implantation tract <b>280</b>.

<figref idref="DRAWINGS">FIG. 22A</figref> further illustrates distal advancement of the adapter tube <b>540</b>, the retaining adapter <b>542</b>, the clip <b>580</b>, the vascular access port <b>400</b>, the push tube <b>550</b>, and the cutting tube <b>560</b>, in unison, over the clamp tube <b>528</b>. Continued advancement in this manner eventually brings the distal end of the retaining adapter <b>542</b> into close proximity or contact with the vessel <b>200</b>.

Once the retaining adapter <b>542</b> is positioned as desired, the anvil pull tube <b>524</b> and the clamp tube <b>528</b> can be pulled in the proximal direction relative to the other components of the implantation assembly <b>500</b>. The anvil pull tube <b>524</b> and the clamp tube <b>528</b> can be pulled in unison such that the wall of the vessel <b>200</b> remains clamped between the anvil <b>522</b> and the clamp <b>526</b>. Accordingly, the portion of the vessel <b>200</b> that is between the clamp anvil <b>522</b> and the clamp <b>526</b> can be pulled proximally through the opening <b>483</b> of the clip <b>480</b>.

<figref idref="DRAWINGS">FIG. 22B</figref> illustrates a stage in which the anvil <b>522</b> and the clamp <b>526</b> have been pulled in a proximal direction sufficiently far that the anvil <b>522</b> is brought into contact with the cutting blade <b>562</b> of the cutting tube <b>560</b>. This action cuts a portion <b>207</b> of the vessel wall from the vessel <b>200</b>, thereby forming an opening in the wall of the vessel <b>200</b>. The cut portion <b>207</b> can remain within the implantation device <b>500</b> during subsequent stages of the implantation.

With continued reference to <figref idref="DRAWINGS">FIG. 22B</figref>, the portion of the wall of the vessel <b>200</b> that is drawn through the opening <b>483</b> of the clip <b>480</b> can surround an outer surface of the anvil <b>522</b>. The close proximity of the teeth <b>488</b> of the clip <b>480</b> to the outer surface of the anvil <b>522</b> can squeeze the vessel wall and prevent it from retracting from the clip <b>480</b>. A peripheral edge <b>208</b> of the vessel <b>200</b>, which results from the severing of the cut portion <b>207</b>, can surround or encircle the outer surface of the anvil <b>522</b>.

With reference to <figref idref="DRAWINGS">FIG. 22C</figref>, once the portion <b>207</b> of the vessel wall has been severed, the push tube <b>550</b> can be advanced distally, which in turn can advance the vascular access port <b>400</b> distally. In the illustrated embodiment, the push tube <b>550</b> presses on the pinnacle region <b>422</b> of the vascular access port <b>400</b>, thereby approximating the vascular access port <b>400</b> to the clip <b>480</b>. The everting members <b>472</b> of the vascular access port <b>400</b> can scoop the peripheral edge <b>208</b> of the vessel <b>200</b> and can thereby evert the vessel wall over the teeth <b>488</b> of the clip <b>480</b>.

As the vascular access port <b>400</b> is advanced distally, the connection prongs <b>484</b> of the clip <b>480</b> are advanced deeper into the connection channels <b>478</b> (see <figref idref="DRAWINGS">FIG. 19</figref>) of the vascular access port <b>400</b>. The interference fit between the retention posts <b>486</b> of the clip <b>480</b> and the retention channels <b>544</b> of the retention adapter <b>542</b> can be sufficiently strong to prevent movement of the clip <b>480</b> away from the retention adapter <b>542</b> during this approximation of the vascular access port <b>400</b> and the clip <b>480</b>.

As shown in <figref idref="DRAWINGS">FIG. 22D</figref>, as additional distally directed force is applied to the vascular access port <b>400</b> via the push tube <b>550</b>, the everted vessel wall is compressed over the teeth <b>488</b> of the clip <b>480</b>. As previously mentioned, the teeth <b>488</b> can grip the vessel wall as they are received into the attachment recesses <b>474</b> (see <figref idref="DRAWINGS">FIG. 19</figref>) of the vascular access port <b>400</b> (substantially without crushing or puncturing the vessel wall, in the illustrated embodiment), and the teeth <b>488</b> thus can retain the vessel wall and prevent it from retracting through the opening <b>483</b> of the clip.

Moreover, the stops <b>476</b> of the vascular access port <b>400</b> can contact the retention posts <b>486</b> of the clip <b>480</b>. The resulting spacing between the base ring <b>482</b> of the clip <b>480</b> and the bottom surface <b>408</b> of the vascular access port <b>400</b> can be sufficiently close to establish a hemostatic seal between the vessel wall and the vascular access port <b>400</b> but sufficiently distanced to prevent crushing of the vessel wall. Additional movement of the push tube <b>550</b> in the distal direction thus can provide sufficient force to eject or disengage the retention posts <b>486</b> from the retention channels <b>544</b> of the retention adapter <b>542</b> without applying any additional force to the vessel wall that could crush it. In some embodiments, the force required to advance the connection prongs <b>484</b> of the clip <b>480</b> into the connection channels <b>478</b> (see <figref idref="DRAWINGS">FIG. 19</figref>) of the vascular access port <b>400</b> is less than the force required to disengage the retention prongs <b>486</b> of the clip <b>480</b> from the retention channels <b>544</b> of the retaining adapter <b>542</b>.

<figref idref="DRAWINGS">FIG. 22E</figref> depicts a stage after the vascular access port <b>400</b> has been attached to the blood vessel <b>200</b> and the retention posts <b>486</b> have been ejected from the retention channels <b>544</b> in which the implantation assembly <b>500</b> is being removed from the vascular access port <b>400</b>. As shown, the cutting tube <b>560</b>, the clamp tube <b>528</b> (and all attachments thereto), and the anvil pull tube <b>524</b> (and all attachments thereto) are moved proximally through the primary passageway <b>464</b> of the vascular access port <b>400</b>. Removal of the introducer tip <b>520</b> proximally past an upper end of the flaps <b>461</b> can permit the flaps <b>461</b> to transition automatically or naturally from the open orientation to the closed orientation to thereby seal the primary passageway <b>464</b>. After removal of the implantation assembly <b>500</b> therefrom, the implantation tract <b>280</b> can be closed in any suitable manner and allowed to heal.

<figref idref="DRAWINGS">FIGS. 23A-23C</figref> illustrate various stages of a method of using an implanted vascular access port <b>400</b>. <figref idref="DRAWINGS">FIG. 23A</figref> illustrates the implanted vascular access port <b>400</b> just after the implantation tract <b>280</b> has been closed. As shown, the plug <b>452</b> seals the channel <b>434</b>. The flaps <b>461</b> are in the closed orientation and seal the upper opening <b>468</b> of the primary passageway <b>464</b>. The lower opening <b>466</b> of the primary passageway <b>464</b> is open and is in fluid communication with an interior of the vessel <b>200</b>. Accordingly, blood <b>268</b> is permitted to enter the primary passageway <b>464</b> but is not permitted to exit the vascular access port <b>400</b> via either the upper opening <b>468</b> of the primary passageway <b>464</b> or the channel <b>434</b>.

<figref idref="DRAWINGS">FIG. 23B</figref> illustrates a stage after the healing has taken place. In particular, the plug <b>452</b> has been absorbed and replaced with tissue, as has blood <b>268</b> that previously filled the primary passageway <b>464</b>. The tissue can be firmly attached to the tissue ingrowth region <b>469</b> of the primary passageway <b>464</b>. Also shown is a membrane <b>282</b> that has formed naturally over the lower opening <b>466</b> of the primary passageway <b>464</b>, thereby sealing the lower opening <b>466</b>. The natural membrane <b>282</b> can be a continuation of the wall of the vessel <b>200</b>. In some embodiments, absorption of the plug <b>452</b> and/or creation of the membrane <b>282</b> can take place within a period of no more than about one week or no more than about two weeks after implantation of the vascular access port <b>400</b>.

Once the membrane <b>282</b> has formed, methods of using the vascular access port <b>400</b> can proceed in the same manner as methods described above with respect to the vascular access port <b>100</b>. For example, a clinician can palpate the skin of a patient to locate and determine the orientation of the vascular access port <b>400</b> in a manner similar to that illustrated in and discussed with respect to <figref idref="DRAWINGS">FIG. 11A</figref>.

As shown in <figref idref="DRAWINGS">FIG. 23C</figref> an access device <b>144</b> can directly access a lumen <b>262</b> of the vessel <b>200</b> via the vascular access port <b>400</b>. In particular, <figref idref="DRAWINGS">FIG. 23C</figref> is similar to <figref idref="DRAWINGS">FIG. 11B</figref> and shows an initial access event. The access device <b>144</b> has been advanced through the skin of a patient to form an insertion tract <b>264</b> therein, has been advanced through the guidance passageway <b>430</b> (specifically, through the channel <b>434</b> and the distal opening <b>450</b> of the guidance passageway <b>430</b>), through a lower end of the primary passageway <b>464</b>, through the lower opening <b>466</b>, and through the membrane <b>282</b>. Stated otherwise, a central axis of the guidance passageway <b>430</b> (e.g., a central axis of the channel <b>434</b>) extends through the lower opening <b>466</b>, and the guidance passageway <b>430</b> constrains the access device <b>144</b> to move along the central axis and through the lower opening <b>466</b>. The access device <b>144</b> thus can create an insertion site <b>266</b> in the vessel <b>200</b>. Additional procedures relative to repeated access of the insertion site <b>266</b> via the vascular access port <b>400</b> can be as described above with respect to <figref idref="DRAWINGS">FIGS. 11C-11E</figref>.

<figref idref="DRAWINGS">FIGS. 24 and 25</figref> illustrate another embodiment of a vascular access port <b>600</b>, which can resemble the vascular access ports <b>100</b>, <b>400</b> described above. The vascular access port <b>600</b> can be implanted via a percutaneous method, such as by using the percutaneous implantation assembly <b>500</b> described above. The vascular access port <b>600</b> can include a base <b>602</b> and a body <b>604</b>. An attachment region <b>670</b> of the base <b>602</b> can extend beyond an outer surface <b>607</b> of the body <b>604</b>. In the illustrated embodiment, the attachment region <b>670</b> comprises a separate piece that is fixedly attached to the body <b>604</b>. The attachment region <b>670</b> defines a plurality of connection channels <b>678</b>, two of which extend through the base <b>602</b> and are spaced outwardly from the body <b>604</b>, and two of which extend through the base <b>602</b> and into the body <b>604</b> but do not extend through an entirety thereof.

The connection channels <b>678</b> can be configured to receive therein connection posts <b>684</b> of a clip <b>680</b>. In the illustrated embodiment, the each connection posts <b>684</b> includes a single prong, which thickens in a distal direction and is configured to provide an increasingly tight interference fit within a connection channel <b>678</b> as the clip <b>680</b> is approximated to the vascular access port <b>600</b>.

The attachment region <b>670</b> can include attachment recesses <b>674</b> having sidewalls that are spaced further from each other at an entry end thereof and are rounded at a base thereof. As shown in <figref idref="DRAWINGS">FIG. 25</figref>, the entry ends of the attachment recesses <b>674</b> can be spaced from the teeth <b>688</b>, which can permit the teeth <b>688</b> of the clip <b>680</b> to grip a vessel wall without puncturing it. The attachment region <b>670</b> can include everting members <b>672</b> that are interdigitated with the teeth <b>688</b> when the clip <b>680</b> is approximated to the vascular access port <b>600</b>. Additionally, the attachment region <b>670</b> can include stops <b>676</b> that are positioned more centrally and contact a base ring <b>682</b> of the clip <b>680</b> when the clip <b>680</b> is approximated to the vascular access port <b>600</b>.

The vascular access port <b>600</b> can include a seal or sealing device <b>660</b> at an upper end thereof. The sealing member <b>660</b> can include a tube <b>663</b> that is closed at an end thereof in any suitable manner, such as via a purse-string suture <b>665</b>. The tube <b>663</b> can comprise any suitable material, such as, for example, one or more of urethane, polytetrafluoroethylene (PTFE), PGA, PLGA, Dacron, collagen, or any suitable resorbable material listed above.

In some embodiments, the tube <b>663</b> defines an outer diameter that is smaller than an inner diameter of a push tube <b>550</b> (see <figref idref="DRAWINGS">FIG. 22A</figref>) and an inner diameter that is larger than an outer diameter of a cutting tube <b>560</b> (see <figref idref="DRAWINGS">FIG. 22A</figref>). Accordingly, during implantation of the vascular access port <b>600</b>, the tube <b>663</b> can be concentric with and positioned between the push tube <b>550</b> and the cutting tube <b>560</b>. After the vascular access port <b>600</b> has been attached to a vessel, the push tube <b>550</b> and the cutting tube <b>560</b> can be removed. A proximal end of the tube <b>663</b> may be external to the skin of the patient at this stage, and can be clamped to prevent blood loss. The purse-string suture <b>665</b> could be in place prior to commencing the implantation, or can be provided after removal of the push tube <b>550</b> and the cutting tube <b>560</b>. The purse-string suture <b>665</b> can be cinched tight, and the proximal portion of the tube <b>663</b> can be severed from a distal portion thereof at a position above the suture <b>665</b> (e.g., can be cut from the portion shown in <figref idref="DRAWINGS">FIGS. 24 and 25</figref>). The vascular access port <b>600</b> thus can be entirely subcutaneous once implanted. In other embodiments, the sealing device <b>660</b> can include a plug in place of the tube <b>663</b>, which can be inserted into the vascular access port <b>600</b> after removal of the push tube <b>550</b> and the cutting tube <b>560</b>.

The vascular access port <b>600</b> can include a single palpation projection <b>646</b> at an upper border of a guidance channel <b>630</b>. In the illustrated embodiment, the palpation projection <b>646</b> is lower than an upper end of the tube <b>663</b>.

<figref idref="DRAWINGS">FIG. 26</figref> illustrates another embodiment of a vascular access port <b>700</b>, which can resemble the vascular access ports <b>100</b>, <b>400</b>, <b>600</b> described above. The vascular access port <b>700</b> can be implanted via a percutaneous method, such via the percutaneous implantation assembly <b>500</b> described above. The vascular access port <b>700</b> can include a base <b>702</b> and a body <b>704</b>. The base <b>702</b> can include an attachment region <b>770</b> similar to the attachment region <b>670</b>. Although a circular arrangement of the attachment region <b>770</b> is shown, other arrangements are also possible (e.g., oval-shaped).

A passageway <b>731</b> can extend through the body <b>702</b> and the base <b>702</b>. The body <b>704</b> can include a palpation projection <b>746</b> that borders or encompasses a significant portion of the passageway <b>731</b>. For example, in the illustrated embodiment, the palpation projection <b>746</b> encompasses more than ¾ of the passageway. An inner wall of the palpation projection <b>746</b> can be substantially perpendicular to a plane defined by a lower portion of the body <b>704</b>. The palpation projection <b>746</b> can serve as a backstop that can prevent an access device <b>144</b> from overshooting the passageway <b>731</b>. In other embodiments, the vascular access port <b>700</b> does not include a palpation projection <b>746</b>.

The vascular access port <b>700</b> can include a sealing member <b>760</b>, such as any of the sealing members <b>560</b>, <b>660</b> described above. In the illustrated embodiment, the sealing member <b>760</b> comprises a plug <b>767</b>, which can be resorbable or otherwise configured to be assimilated into the body and replaced with tissue. For example, the plug <b>767</b> can comprise any suitable material from the list of resorbable materials set forth above, collagen, plyurethane foam, etc. In some embodiments, the plug <b>452</b> comprises Surgicel®. Once the vascular access port <b>700</b> is implanted, a vessel membrane <b>282</b> can form over the passageway <b>731</b> and seal the contents of the vessel therefrom. In other embodiments, the vascular access port <b>700</b> can be implanted without a sealing member <b>760</b>.

<figref idref="DRAWINGS">FIG. 27</figref> illustrates an embodiment of a system <b>800</b> configured for the external treatment of blood. The system <b>800</b> is similar to the system <b>300</b> described above. The system <b>800</b> includes two vascular access ports <b>100</b>A, <b>100</b>B, which can resemble any of the ports described above. Both of the ports <b>100</b>A, <b>100</b>B are shown attached to a vessel <b>200</b> that is associated with an arteriovenous fistula <b>218</b>. One port <b>100</b>A is directed upstream such that a forward end thereof points in a direction opposite to the flow of blood through the vessel <b>200</b>, and the other port <b>100</b>B is directed downstream such that a forward end thereof points in the direction of the blood flow through the vessel <b>200</b>, although other arrangements are possible. A separate access device <b>144</b> (e.g., fistula needle or over-the-needle catheter) may be introduced into each of the ports <b>100</b>A, <b>100</b>B via any of the methods described above and connected to a blood treatment system <b>802</b> (e.g., hemodialysis machine) via any suitable passageways <b>2004</b> (e.g., tubing).

Blood treatment then can then be performed. The first port <b>100</b>A can be an uptake port through which blood is removed from the vessel <b>200</b> and delivered to the blood treatment system <b>802</b>, and the second port <b>100</b>B can be a return port through which treated blood is returned to the vessel <b>200</b> from the blood treatment system <b>802</b>. Accordingly, in use, blood is removed from the patient via an access device <b>144</b> that is within the first port <b>100</b>A and delivered to the blood treatment system <b>802</b>. The removed blood is treated in any suitable manner via the blood treatment system <b>802</b>. Treated blood is returned to the patient via an access device <b>144</b> that is within the second port <b>100</b>B.

In other embodiments, the system <b>800</b> can comprise only a single vascular access port <b>100</b>A or <b>100</b>B. Blood treatment may be conducted thereby via any suitable method (e.g., a single-needle hemodialysis technique). In still other embodiments, the system <b>800</b> includes more than two vascular access ports <b>100</b>A, <b>100</b>B. A clinician thus can rotate among the ports <b>100</b>A, <b>100</b>B, thereby leaving one or more of the ports unused during any given blood treatment session.

As can be appreciated from the foregoing, embodiments of vascular access ports can be sized and dimensioned to reside within a patient and beneath an outer surface of the skin of the patient. For example, the vascular access ports can be sized to fit between a vessel (e.g., any suitable artery or vein, such as, for example, the cephalic, basilic, femoral, jugular, or subclavian vein) and the epidermis of an animal subject.

Moreover, embodiments of one or more vascular access ports can be included in various embodiments of kits. For example, in some embodiments, a kit can comprise a vascular access port such as any of the ports described above. The kit can further include one or more of: one or more sutures or other attachment devices by which the port can be attached to a vessel, one or more synthetic grafts (which may be pre-attached to the port or separate therefrom), one or more pads of ingrowth-inducing material (which may be pre-attached to the port or separate therefrom), and one or more additional vascular access ports of the same configuration and/or of one or more different configurations (e.g., different size, shape, etc.). For example, in some embodiments, the kit can include multiple ports such that a practitioner can select one or more of the ports for implantation. In further embodiments, the kit can include ports of different sizes such that the practitioner can further select an appropriate port (or appropriate ports) based on the particular anatomy of a patient and/or on the target location of the port (or ports).

It is noted that while many of the examples provided herein relate to the use of vascular access ports with blood vessels, this method of disclosure is employed for the sake of convenience and efficiency, but should not be construed as limiting of the types of procedures with which embodiments may be used. Indeed, embodiments of the apparatus, methods, and systems disclosed herein can be used with vessels other than blood vessels, such as, for example, vessels within the gastrointestinal tract. Accordingly, the term “vessel” is a broad term that can include any hollow or walled organ or structure of a living organism, whether natural or synthetic.

It will be understood by those having skill in the art that changes may be made to the details of the above-described embodiments without departing from the underlying principles presented herein. For example, any suitable combination of various embodiments, or the features thereof, is contemplated.

Likewise, although symmetries are present in the illustrated embodiments, some embodiments may be asymmetrical. For example in some embodiments, a guidance passageway of a vascular access port may extend generally at an angle relative to a vertical longitudinal plane through the port such that a funnel region may more readily receive an access device therein at one side of the port as opposed to an opposite side thereof. Such arrangements may be beneficial in some applications where a port is implanted on a vessel that may more easily be reached from a direction that is not generally aligned with (e.g., nonparallel to) the vessel.

Any methods disclosed herein comprise one or more steps or actions for performing the described method. The method steps and/or actions may be interchanged with one another. In other words, unless a specific order of steps or actions is required for proper operation of the embodiment, the order and/or use of specific steps and/or actions may be modified.

References to approximations are made throughout this specification, such as by use of the terms “about” or “approximately.” For each such reference, it is to be understood that, in some embodiments, the value, feature, or characteristic may be specified without approximation. For example, although it is noted that in various embodiments, the height H of the vascular access port <b>100</b> is no greater than about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 millimeters, it is understood that in some embodiments, the height H of the vascular access port <b>100</b> is no greater than 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 millimeters.

Reference throughout this specification to “an embodiment” or “the embodiment” means that a particular feature, structure or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, the quoted phrases, or variations thereof, as recited throughout this specification are not necessarily all referring to the same embodiment.

Similarly, it should be appreciated that in the above description of embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure. This method of disclosure, however, is not to be interpreted as reflecting an intention that any claim require more features than those expressly recited in that claim. Rather, as the following claims reflect, inventive aspects lie in a combination of fewer than all features of any single foregoing disclosed embodiment. Thus, the claims following this Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment. This disclosure includes all permutations of the independent claims with their dependent claims.

Recitation in the claims of the term “first” with respect to a feature or element does not necessarily imply the existence of a second or additional such feature or element. Elements specifically recited in means-plus-function format, if any, are intended to be construed in accordance with 35 U.S.C. §112 ¶6. Embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows.